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Archive-name: aquaria/reefkeeper-faq/part1
Rec-aquaria-archive-name: reefkeeper-faq/part1 Alt-aquaria-archive-name: reefkeeper-faq/part1 Sci-aquaria-archive-name: reefkeeper-faq/part1 Posting-Frequency: monthly See reader questions & answers on this topic! - Help others by sharing your knowledge
Reef Keepers Frequently Asked Questions (Part 1 of 3)
Note: This header is copied into all three parts
(Well, more or less. Actually, this is a composite document written
by many folks. It contains information each participant felt was
basic information required for anyone considering maintaining a reef
tank. In reality, it's turned into a bit of a reference document.
Some of the information has been taken from public forums like the
Internet UseNet *.aquaria groups. Credit to the authors of such
information is given next to their contribution.)
Note that starting with 1.12, new and/or changed items are marked with
an "*" in the far left column.
*Release 1.12 - 17 Aug, 1994 (more corrections and minor area expansions)
Release 1.11 - 18 Apr, 1994 (some corrections and minor area expansions)
Release 1.10 - 9 Sep, 1993 (Significant additions to test kit and protein
skimming sections. Many spelling and grammar
corrections, some style and format alterations.)
Release 1.02 - September 1st, 1993 (Reorganized, split into 3 pieces)
Release 1.01 - July 1st, 1993 (First Public Release)
Release 1.00 - May 12th, 1993
*Copyright 1993, 1994, ReefKeepers, All Rights Reserved
ReefKeepers, for purposes of the copyright, is the group of authors
listed at the end of this 3-part document. Permission is granted for
it to be copied (unmodified) in either electronic or hardcopy form by
nonprofit organizations if it is copied in its entirety and used in
stand-alone form. This document may not otherwise be published,
posted, uploaded, replicated or copied by any method, electronic or
physical, without the explicit permission of ALL of the listed
contributors.
The authors of this document have kindly spent the time to bring you
their opinions. They are not liable in any form or fashion, nor are
their employers, for how you use this information. Their opinions
should not be construed as fact; don't blame them if your tank has
problems.
You may get a copy of this FAQ via FTP from the following sites:
percula.acs.uci.edu (128.200.34.15) /reefkeepers/faq
*ftp.cco.caltech.edu (131.215.48.151) /pub/aquaria/FAQfiles/Reefkeepers
/---------------------------------------------------------------------------/
Table of Contents
Basic Sections:
Part 1)
1.0 Water (Filters/Additives/Test Kits)
1.1 Source Water - City Mains Water Is Not Good Enough
1.1.1 Background
1.1.2 DI Filters
1.1.3 RO Filters
1.1.4 Further Comments About Water
1.2 Additives
1.3 Testable Parameters
1.3.1 Alkalinity
1.3.2 Calcium
1.3.3 pH
1.3.4 Nitrate (NO3)
1.3.5 Phosphate (PO4)
1.3.6 Specific Gravity
1.4 Water Changes
2.0 Filtration and Equipment
2.1 Live Rock
2.2 Protein Skimmers
2.2.1 Counter Current Air Driven Protein Skimmers
2.2.2 Venturi Protein Skimmers
2.2.3 Protein Skimmer Considerations
2.3 Granular Activated Carbon (GAC)
2.4 Other Chemical Filter Media (X-Whatever)
2.5 Mechanical Filtration
2.6 Under Gravel Filters (UGF)
2.7 Reverse Flow UGFs (RUGF)
2.8 Trickle Filters
2.9 Algae Scrubbers (somewhat long)
2.10 Live Sand
3.0 Lights
* 3.1 General Discussion
* 3.2 Detail Discussion
* 3.3 Lighting Data
4.0 Cost Estimates
Part 2)
5.0 Stock
5.1 Common to Scientific Name Cross Reference
5.2 Coral Aggression Chart
5.3 Corals [Cnidaria (Anthozoa)]
5.4 Shelled Things
5.5 Algae
5.6 Possible Problems
* 5.7 Hermit Crabs
Part 3)
6.0 General Catalogs
7.0 Questions and Answers
8.0 Book Review
9.0 Useful Tables
10.0 Credits
=========================================================================
1.0 Water
1.1 Source Water - City Mains Water Is Not Good Enough
1.1.1 Background
* US EPA requirements for water quality from municipal sources are
insufficiently pure for reef tank usage. For instance, the EPA
standard for Nitrate (as NO3-N) is 10.0 mg/l, over twice the
recommended maximum level. Extremely toxic (to inverts) heavy
metals such as copper are allowed at levels as high as 1 mg/l.
Most public water supplies have contaminates well below the EPA
levels and some reef tanks have done fine on some public supplies.
In general, however, it is recommended that some form of post
processing be performed on public water before it is introduced
into the reef tank.
Although some people have access to distilled, de-ionized or
reverse osmosis water from public sources, most will use a home
sized system to produce their tank water. The two most common
systems used are de-ionization resins, and reverse osmosis
membranes.
1.1.2 DI filters
De-ionization (DI) units come in two basic varieties: mixed bed and
separate bed. Two chambers are used in separate bed units, one
for anion resins (to filter negatively charged ions), the other
for cation resins (to filter positively charged ions). Mixed bed
units use a single chamber with a mix of anion and cation resins.
DI units are 100% water efficient with no waste water. They are
typically rated in terms of grains of capacity (a grain is 0.065
grams). Once the capacity of the unit is reached it either needs
to be replaced or recharged (using strong acids and bases).
Recharging is normally only an option for separate bed units.
A quick check of the local water quality charts (normally
available free from the water supply company) will reveal the
water purification capacity of a given DI unit. For example, if a
unit rated at 1000 grains is purchased and the local water supply
has a hardness of 123 mg/l (Missouri River, USA), then the unit
capacity is (1000*0.065)/0.123 = 528 liters = 139.5 gallons of
purified water.
Water production rates for DI units varies, but is typically
around 10-15 gallons/hour.
1.1.3 RO Filters
Reverse osmosis (RO) units are normally based upon one of two
membrane technologies: cellulose triacetate (CTA) and thin film
composite (TFC). CTA based systems are typically cheaper and do
not filter as well (90-95% rejection rates). TFC based systems
cost more but have higher pollution rejection rates (95%-98%).
CTA membranes break down over time due to bacterial attack whereas
TFC membranes are more or less impervious to this. CTA units are
not recommended for reef tank purposes.
RO filters work by forcing water under pressure against the
membrane. The membranes allow the small water molecules to pass
through while rejecting most of the larger contaminates.
RO units waste a lot of water. The membrane usually has 4-6 times
as much water passing by it as it allows though. Unfortunately,
the more water wasted, the better the membrane usually is at
rejecting pollutants. Also, higher waste water flows are usually
associated with longer membrane life. What this means in practice
is that 300 gallons of total water may be required to produce 50
gallons of purified water.
Like any filter, RO membranes will eventually clog and need to be
replaced. Replacement membranes cost around $50-$100. Prefilters
are often placed in front of the membrane to help lengthen the
lifetime. These filters commonly consist of a micron sediment
filter and a carbon block filter. The micron filter removes large
particles and the carbon filter removes chlorine, large organic
molecules and some heavy metals. Of course, the use of prefilters
makes initial unit cost more expensive but they should pay for
themselves in longer membrane life.
RO units are rated in terms of gallons per day of output with
10-50 gallon/day units typically available. Note that the waste
water produced by a RO unit is fine for hard water loving
freshwater fish such as Rift Lake cichlids. Some route the reject
water to the family garden.
The Spectapure brand of RO units has a good reputation.
1.1.4 Further Comments About Water
The ultimate in home water purification comes from combining the
two technologies and processing the water from an RO unit though a
DI unit. If a very high grade DI unit is used, water equivalent
to triple distillation purification levels can be achieved. Since
the water entering the DI unit can be 50 times purer than
tapwater, the DI unit can process 50 times as much before the
resins are exhausted. This significantly reduces the replacement
or recharging cost of the DI unit.
If only one filter can be afforded, and waste water is not a concern,
then it is recommended that a TFC RO unit with pre-filters be purchased.
If waste water is a concern, or if only a small quantity of make-up
water will be required (say, for a single 20 gallon tank), then a DI
unit would be the preferred choice.
City water is unstable. Many cities modify their treatment
process several times a year, dramatically changing its
suitability for reef usage. For instance, Portland has great reef
water - most, but not all, of the year.
1.2 Additives
Calcium (Ca) - required addition. A range of 400-450 ppm Ca++
(10-11 mM) is recommended. The preferred method is the usage of
Kalkwasser (Limewater) for all evaporation make-up water. The use
of Calcium Chloride (CaCl2) is known to cause problems with alkalinity
(provable by balancing the relavent chemical reactions occuring in the
tank when CaCl2 is added). Still, CaCl2 is occassionally useful to
repair serious Ca++ deficits.
Chelated calcium:
The efficacy of chelated calcium products available for reef aquaria is
questionable. To the best of our knowledge, there exists no scientific
evidence indicating that chelated calcium is especially available to
corals and other CaCO3 depositing invertebrates. Nothing is known about
the uptake of chelated calcium products by coral. And most importantly,
there exists no evidence showing that chelated calcium products support
stony coral growth rates in excess of, or even *comparable to* growth
rates documented in aquaria where calcium is supplied as aqueous Ca(OH)2
[kalkwasser.]
Chelated calcium products also interfere with the ability to measure
actual calcium levels in the aquarium. In particular, chelated calcium
cannot be measured by any kit which uses EDTA titration, including the
highly recommended HACH kit. Some people find the SeaChem kit, which
does measure chelated calcium, to be impossible to read with any
accuracy.
Until such a time as vendors supplying chelated calcium products make
available well conceived, carefully documented uptake and growth studies
with their products, or the same experiments are performed and published
by third parties, we regard the use of chelated calcium products in the
reef aquarium to be experimental at best, especially when kalkwasser
and other non-chelated calcium sources are KNOWN to us to support the
growth and even reproduction of stony corals in the home aquarium.
Iodine (I) - enhances soft coral growth. It is removed by
skimming.
Strontium (Sr) - used rapidly by most hard corals (weekly
additions usually performed).
Buffers - increase alkalinity and control pH. Desired range is
2.5-3.5 meq/L (7-10 dKH) alkalinity. Alkalinity can be raised by the
addition of one of many commercial buffer compounds. The addition of
kalkwasser (saturated Ca(OH)2 solution - also known as
"limewater"), which is often done to maintain calcium levels, will
also raise the alkalinity level. SeaChem's Marine Buffer, Reef
Builder and Kent's Superbuffer dKH are popular. The Coralife and
Thiel buffer products have had less favorable reviews.
Iron (Fe) - Used by algaes. Add this if you want good macroalgae
growth. Be sure that macroalgae growth is favored or else plague
levels of hair algae may result.
Copper (Cu) - Used as a medication in fish-only tanks. Copper is
highly toxic to invertebrates, even in very small concentrations.
DO NOT USE THIS, IN ANY FORM, EVER, IN A REEF TANK OR ANY TANK
WHICH CONTAINS INVERTEBRATES. PERIOD!
Other additives, especially the commercial "secret formula"
mixtures, are more controversial. Some people report good results
from some of them other people report disaster or no effect.
Experiment cautiously with them if desired.
1.3 Testable Parameters
Note: parts per million (ppm) and milligrams per liter (mg/l) are
virtually identical in seawater and the units are used
synonymously in this document.
1.3.1 Alkalinity
Alkalinity is a measure of the acid buffering capacity of a solution.
That is, it is a measure of the ability of a solution to resist a
decrease in pH when acids are added. Since acids are
normally produced by the biological action of the reef tank
contents, alkalinity in a closed system has a natural tendency to
go down. Additives are used to keep it at a proper level.
Correct alkalinity levels allow hard corals and coralline algae to
properly secrete new skeletal material. When alkalinity levels
drop, the carbonate ions needed are not available and the process
slows or stops.
Alkalinity is measured in one of three units: milliequivalents per
liter (meq/l), German degrees of hardness (dKH) or parts per
million of calcium carbonate (ppm CaCO3). Any of the units may be
employed but dKH is most commonly used in the aquarium hobby and
meq/l is used exclusively in modern scientific literature. The
conversion for the three units is:
1 meq/l = 2.8 dKH = 50 ppm CaCO3
[As an aside, there is an imperial unit of alkalinity and hardness
which is 'grains per gallon'. The water softening industry uses
this unit. 1 gpg = 17 ppm CaCO3.]
A word of caution about the ppm CaCO3 unit is in order. The 'ppm
CaCO3' unit reports the concentration of CaCO3 in pure water that
would provide the same buffering capacity as the water sample in
question. This does not mean the sample contains that much CaCO3.
In fact, it tells you nothing about how much of the buffering is
due to carbonates, it is only a measure of equivalency.
Alkalinity is often confused with carbonate hardness since both
participate in acid neutralization and test kits may express both
in either of the three units. However, carbonate hardness is
technically a measure of only the carbonate species in equilibria
whereas alkalinity measures the total acid binding ions present
which may include sulfates, hydroxides, borates and others in
addition to carbonates. In natural seawater, though, carbonates
make up 96% of the alkalinity so equating alkalinity with
carbonate hardness isn't too far off.
Recommended values for alkalinity vary depending on who's work you
read. Natural surface seawater has an alkalinity of about 2.4
meq/l. Following are levels recommended by various authors.
From John Tullock (1991) "The Reef Tank Owner's Manual":
page 46 - Alkalinity range should be 3.5 to 5.0 meq/l.
page 94 - Alkalinity reading of 2.5-5.0 meq/l is proper.
page 188- Alkalinity should be about 3.5 meq/l. (In reference
to maintaining Tridacna clams.)
Albert Thiel (1989), in "Small Reef Aquarium Basics" recommends
5.35-6.45 meq/l. This is an artificially high level which may
initiate a "snowstorm" of CaCO3 precipitate. Most reef aquarists
do not believe in such extreme and unnatural levels and recommend
3.0-3.5 meq/l as a good range instead.
The chemistry of how alkalinity, pH, CO2, carbonate, bicarbonate,
and other ions interrelate is fairly complex and is beyond the
scope and detail of this document.
Some recommended test kits for alkalinity are the SeaTest kit and
the LaMotte kit. The SeaTest kit is very inexpensive and is one
* of the few SeaTest kits suitable for reef use. The SeaTest kit
measures in division of 0.5 meq/l or, if the amount of solution is
doubled, 0.25 meq/l. The SeaTest kit uses titration in which the
acid and indicator are included in the same reagent. The LaMotte
kit is a little more expensive, though still fairly cheap, and is
somewhat more accurate. The unit of titration is 4 ppm CaCO3
although in practice, one drop from the titration tube may be up
to twice this amount making the resolution about 0.15 meq/l. The
Lamotte kit has a separate indicator tablet and acid reagent which
is a nice feature.
1.3.2 Calcium
Calcium content is referred to as 'calcium hardness' and is
measured either in parts per million of calcium ion (ppm Ca++) or
parts per million equivalent calcium carbonate (ppm CaCO3).
Calcium hardness is often confused with alkalinity and carbonate
hardness since the 'ppm CaCO3' unit may be used for all three. As
with alkalinity, a calcium level expressed as X ppm CaCO3 does not
imply that X ppm of calcium carbonate is present in the tank; it
merely states that the sample contains an equivalent amount of
calcium as if X ppm of CaCO3 were added to pure water. The
reading also does not tell you how much carbonate is present.
Calcium hardness test kits are different from alkalinity kits.
Some people have reported difficulties with the LaMotte calcium
hardness kit. The Hach 'Total Hardness and Calcium' kit has not
had these reports. Both express results in ppm CaCO3. The
relationship between CaCO3 and Ca++ is:
1 ppm CaCO3 = 0.4 ppm Ca++
The results from a test kit reading in ppm CaCO3 may be converted
to the molar concentration scale by dividing by 100.
100 ppm CaCO3 = 1 mM Ca++
40 ppm Ca++ = 1 mM Ca++
Calcium levels of natural surface seawater are around 420 ppm
Ca++ (10.5 mM). In a well running reef tank you will notice, sometimes
dramatic, calcium depletion. Calcium addition in some form is
essential. A calcium level above 400 ppm is required and a range
of 400-450 ppm Ca++ is recommended. Most reefkeeping books (see
bibliography) explain the options for calcium addition.
1.3.3 pH
The suggested reef tank range is 8.0 to 8.3. The pH should hold
its own unless alkalinity is low. If alkalinity is OK but pH is
low there is probably a buildup of organic acids or a serious lack
of gas exchange (low water surface area to volume ratio).
1.3.4 Nitrate (NO3)
Two units are used to measure nitrates: nitrate (NO3-) and nitrate
nitrogen (NO3-N or just N). The ratio is:
1 ppm NO3-N = 4.4 ppm NO3-.
Nitrates themselves may not be a problem but serve as an easily
measured indicator of general water quality. Many hard to test
for compounds like dissolved organics tend to have levels that
correlate well with nitrate levels in typical tanks.
Different authors cite varying upper nitrate values permissible.
No higher than 5 ppm NO3- is a good number with less than 0.25 ppm
recommended. Unpolluted seawater has nitrate values below
detectable levels of hobbyist test kits, so "unmeasurable" is the
goal to strive for.
Most test kits measure nitrate-nitrogen. Do not forget to
multiply by 4.4 to get the ionic nitrate reading. LaMotte makes a
nitrate test kit that will measure down to 0.25 ppm NO3-N. Hach
makes one good to 0.02 ppm NO3-N, about 10x more sensitive, but
you must be sure to order the saltwater reagents. They will only
sell you the saltwater reagents in addition to the regular kit
with the freshwater reagents, not in place of them, which is
annoying. This makes the Hach kit about twice as expensive in the
end as the LaMotte kit but the 10x increase in performance makes
this more acceptable.
1.3.5 Phosphate (PO4)
Phosphates, along with nitrates, are a primary nutrient of algae.
Tanks with "high" levels of phosphates tend to be infested with
hair algae. All authors cite zero ppm PO4 as a good goal. An
upper level 0.1 ppm is recommended by Tullock (1991) with less
than 0.05 ppm given by Thiel (1991).
1.3.6 Specific Gravity
* Short form:
* Specific Gravity is temperature dependant. See the next table for
* a quick lookup of the recommended hydrometer readings. They are
* based upon our recommended S.G. of 1.025 at 60 degrees F.
*
*Degrees F. Hydrometer reading.
* 50 1.0255
* 55 1.0252
* 60 1.0250
* 65 1.0246
* 70 1.0240
* 75 1.0233
* 80 1.0226
* 85 1.0218 (rather hot for most tanks)
* 90 1.0210 (very hot for most tanks)
*
* In more detail:
* 1.025 recommended for reef tanks. Note that virtually all hydrometers
* are calibrated for measurements at a temperature of 60 F. Included
* below is a short table of temperature adjustments. Add the value
* shown to your hydrometer reading to get an accurate reading.
*
*Degrees F. Correction
* 50 -0.0005
* 55 -0.0002
* 60 0.0000
* 65 0.0004
* 70 0.0010
* 75 0.0017
* 80 0.0024
* 85 0.0032
* 90 0.0040
*
*For example: If the hydrometer reads 1.0235 at 80F, the actual
* Specific Gravity is 1.0235 + 0.0024 = 1.0259
*
*Note: If your tank is between 75F and 80F, this means you should
* try and keep your Specific Gravity around 1.0230 to 1.0235.
*
*For all practicle purposes, the scale is linear between data points,
*so you can simply extrapolate between table entrys. For instance,
*78F is 3/5 the distance between 75F and 80F; the difference in corrections
*is 0.0024-0.0017 = 0.0007. 3/5th of 0.0007 is 0.0004. Add the offset
*0.0004 to the base value for 75F of 0.0017 and you get a correction
*value for 78F of 0.0021.
*
*It is fairly common in literature to see references to salinity in terms
*of Parts Per Thousand (PPT). For salinities in the range we are interested
*in, the conversion formulas are:
*
* Salinity = 1.1 + 1300 * (Temperature corrected Specific Gravity - 0.999)
* Temperatur corrected Specific Gravity = ((Salinity - 1.1) / 1300) + 0.999;
*
*Here is a short table of some common values:
*
* Salinity Specific Gravity
* 20 PPT 1.0135
* 25 PPT 1.0174
* 30 PPT 1.0212
* 35 PPT 1.0251 * Typical Ocean Value *
* 40 PPT 1.0289
1.4 Water Changes
"The solution to pollution is dilution". Water changes are used to
correct problems. Minimal changes of 5%/year when all is set up
and running smoothly may suffice. Some feel that an occasional
water change of about 20% every 1-3 month is a reasonable safety
net that may help prevent contaminate buildup and trace element
* depletion problems. Others recommend 5%-10% per week.
2.0 Filtration and Equipment
2.1 Live Rock
Live rock is simply old coral skeletons that have become the home
to multiple small creatures. Typically reef tanks have 1-2 lbs of
live rock per gallon of capacity. Pieces vary in size and shape
from baseball size to dinner plate size in typical tanks. In large
tanks (> 500 gallons) very large pieces of live rock tend to be used.
These pieces may individually weight up to 85lbs (about the limit of
what one person can handle).
The use of live rock greatly increases the bio-diversity in a tank.
However, its primary purpose is to provide a home for bacteria that
provide the biological filtration for the aquarium.
Cheap rock has low amounts of coralline algae and tends to grow
hair algae well. It may be suitable for a soft coral only tank.
Hair algae free coralline encrusted live rock (high quality
Florida and/or pacific (Marshall and Tonga Island) rock is highly
desirable. "Berlin" style tanks use high quality live rock (and
protein skimming) as the primary filtration method with great
success.
2.2 Protein Skimmers
Required equipment. Don't undersize. Common wisdom is that you
can't overskim a tank. Many of the more available commercial
units are useful for tanks only in the 10-20 gallon range.
Anything shorter than about a foot tall is essentially useless.
Unfortunetly, there is no formula to determine the required size
of a skimmer. Amount of organic waste generating organisms (fish,
coral, live rock, etc.) will obviously be the primary variable.
All skimmers should be filled with TINY bubbles and have a milky
white appearance. Any skimmer that doesn't match that requirement
is not working optimally.
Two basic styles of skimmers exist: counter current air driven and
venturi driven. Both styles work fine, both have tradeoffs. Both
require tuning. Expect to spend some time over the first month or
so learning how to keep your skimmer tuned. Below is some
discussion about the two styles.
2.2.1 Counter Current Air Driven Protein Skimmer
These skimmers usually require three pieces of equipment typically
not sold with them: an air pump, air stones and a water pump.
Total skimmer cost depends upon the kinds of equipment needed to
run the skimmer properly.
The water pump injects the water to be skimmed into the unit.
Some people use gravity to feed surface overflow water to the
skimmer or divert part of the main circulation pump's return flow
into the skimmer to eliminate the need for a dedicated pump.
Otherwise a powerhead in the sump usually suffices for the water
pump.
The air pump must be large enough and a sufficient number of air
stones must be driven to make the skimming column milky white. In
some skimmers one medium sized air pump like a Tetra Luft G and
one air stone will be sufficient. Other skimmers need more to
perform optimally.
Air driven skimmers should use limewood air stones which will need
to be replaced from time to time. Cheap limewood air stones have
a reputation of needing to be replaced much more often than high
quality stones. Coralife limewood air stones have a good
reputation. Air stone replacement rate depends on your tank and
skimmer; some people need to change them every 2 weeks others only
after 3-4 months.
A.J. Nilsen recommends a 1x tank volume per hour turnover of both
water and air by counter current air driven skimmers. Others feel
each skimmer has an optimal rate of air and water processing and
that if more skimming is desired then more or bigger skimmers
should be added rather than trying to operate the current one
beyond its optimal performance range.
Some hold that any skimmer under 4' high and 4" in diameter is too
small for anything over about a 20 gallon reef.
2.2.2 Venturi Protein Skimmers
These skimmers use the Bernoulli effect of the venturi valve to
inject air bubbles into the water. This obviates the need of an
air pump and air stones. The penalty is that a relatively large,
high pressure (read expensive and powerhungry) dedicated water
pump is mandatory for the venturi unit to inject sufficient
amounts of air.
A particular commercial venturi skimmer may or may not come with a
water pump. If it does supply a pump, it may or may not be
sufficiently large to run the skimmer properly. At least some of
the venturi skimmers easily available are not very well designed.
Venturi valves require occasional cleaning of the air opening.
This is as simple as reaming the opening out with pipe cleaner
every few days. An acid bath may be required if the unit clogs or
gets coated with mineral deposits.
Most venturi style skimmers are more compact that CC skimmers.
Manufactures state that they are more efficient, since they
(supposedly) inject more air. Many suspect that design constaints
(back pressure severely affects venturi performance) have more
to do with the manufactured height (who would want a top injected
4' skimmer with air only in the top foot of water?). Properly
designed venturi skimmers are tall to maximize air contact time,
and require pumps that can handle backpressure.
2.2.3 Protein Skimmer Considerations
Below are some pros and cons of venturi vs. CC skimmers. Some
people will debate some of the statements.
Venturi skimmers, due to the large water pump needed, have a
higher initial purchase price than CC units for the same amount of
skimming.
The operational cost of a venturi unit is basically just the
electricity bill. A CC unit must sum in electricity consumption
for the water pump and air pump (usually small) plus air stone and
diaphragm replacement. Which one is more cost effective for you
depends upon which equipment you had to buy to run the skimmer
properly, your electricity rate and how often air stones need to
be replaced. Most people find CC skimmers less expensive to both
purchase and operate for the same amount of skimming.
Venturi skimmers are less cumbersome in appearance and in
operation. They are usually smaller and quieter. They are on the
* whole more hassle free. The powerful pump required for venturi
* skimmers may, however, add considerable heat to the water.
* One general note on water pumps: The amount of heat added to
* the water varies by brand, design, usage, and placement. Basically,
* the more efficient the pump (gallons delivered at a given pressure
* for a given power usage), the cooler it will run. Restricting
* the output of the pump will generally increase the water temperature.
* (Never restrict the intake of a centrifigal pump!) Obviously, an
* air cooled pump will increase your tank temperature less than a
* submersible (and therefore tank water cooled) pump will.
2.3 Granular Activated Carbon
Some debate about its usage. Most use it at least a few days a
month, some continuously. Many brands have problems with
phosphate leaching.
2.4 Other Chemical Filter Media
X-Nitrate, X-Phosphate, Polyfilters, Chemi-pure, etc. - probably
not needed in established, balanced reef aquaria. A prominent
manufacturer of these materials was either unwilling or unable
to supply capacities for removing the named compounds from
seawater. May cause adverse reactions in some inverts.
2.5 Mechanical filtration
This is an area of interest currently being debated. Originally
the FAQ stated:
Good idea to pre-filter skimmer water. Floss works fine and is
cheap and disposable. Sponges work well, but require cleaning
twice a week or so. Natural sponges with a medium fine or fine
pore size are recommended. Some people don't use mechanical
filtration, allowing detritus to settle in places for removal by
siphoning. Some of these people make dedicated "settling tanks"
to trap debris in a convenient place.
Julian Sprung suggests not pre-filtering skimmer water as skimmers
will remove particulates (rather than trapping them as a pre-filter
would do). Spotte confirms this and terms this filtering mechanism
as 'froth floatation'.
Many members of the group of authors do not use mechanical filtration.
They believe that such systems filter out the plankton that is used
as food by many marine organisms. Some members use "live sand" setups,
with detrivores. Others routinely siphon accumulated detritus.
Use of a mechanical filter for short periods may help when attempting to
resolve specific problems, such as a hair algae outbreak.
2.6 Under Gravel Filters (UGF)
Not appropriate for a Reef Tank. Although they will work for 6
months or so, eventually detritus buildup will cause a nitrate
problem. Long term, it's virtually impossible to keep nitrates
below about 40 ppm NO3- which is way too high for corals.
2.7 Reverse Flow UGFs
An attempt to solve the detritus buildup problem associated with
normal flow UGFs. It's a good idea that doesn't work well in
practice. This system has problems with uneven water flow due to
channeling within the bottom gravel.
2.8 Trickle Filters
Also known as Wet/Dry Filters. An improvement over UGF and RUGF
filters. Nitrates can be kept low (say, around 5 ppm) with
adequate water changes. It does not seem to be possible to keep
nitrates very low (less than 1 ppm) if a trickle filter is the
sole biological filtration. Those that report less than 1 ppm
normally have adequate live rock, and find that their Nitrates
remain low even (and often get lower) when they remove all the
bio-material from their trickle filters (turning them into plain
sumps, useful for holding carbon and as a water reservoir).
2.9 Algae Scrubbers (long)
Summary: the jury is still out. May help, may hurt, not currently
recommended, especially as the sole filter. The topic is
controversial. Below is some discussion about it.
In most healthy natural communities, particularly coral reefs,
dissolved nutrients are scarce. In aquaria, by contrast,
nutrients in the form of dissolved inorganic nitrogen, or DIN, (a
collective term for ammonia, nitrites, and nitrates) accumulate
very rapidly as fish and other organisms excrete these wastes.
The most basic problem in any aquarium is limiting the
accumulation of DIN.
In reef aquaria, DIN is consumed by the community of organisms on
the live rock. It is uncertain what relative contribution is made
by bacteria as opposed to algaes, but it is certain that the live
rock community as a whole can remove a substantial amount of DIN
from a reef aquarium. In fact, it is quite possible to run a reef
tank with no biological filtration (DIN consumption) other than
that which takes place on the rock. This method is part of what
is now known in the United States as the "Berlin school" of
reefkeeping.
Other schools of thought utilize additional biological filtration
in separate filters. Traditional reef tanks supplement the
filtration provided by the reef (often not acknowledging the role
of the reef itself) with bacteria-based trickle filters. Many
readers probably learned this technique first, as it has been the
dominant method in the United States amateur hobby for some time.
Yet another approach uses algaes, which are also capable of
utilizing inorganic nitrogen directly. An algae filter, or algal
scrubber as it is usually called, is simply a biological filter
which utilizes a colony of algae rather than bacteria as consumers
of inorganic nitrogen.
Algal scrubbers are not new; they are discussed in Martin Moe's
(1989) excellent _Marine Aquarium Reference: Systems and
Invertebrates_, for example. However, algae filters have been
regarded in the past as too bulky and inefficient to be the sole
filter for a aquarium. The recent surge of interest in algal
scrubbers seems to have been generated by Adey and Loveland's book
_Dynamic Aquaria_ (1991). They discuss both techniques which
allow an algal scrubber to be compact and efficient and also a
number of arguments as to why they are preferable to other
filtration methods.
One reason to use an algal scrubber according to Adey and Loveland
is that it mirrors the way DIN is cycled in nature. They claim
that perhaps 70-90% of the DIN in reef communities is consumed by
algae, rather than by bacteria. The two methods produce rather
different water chemistry; for example, algae are net producers of
oxygen and remove carbon dioxide, while a bacterial filter
consumes oxygen and produces carbon dioxide. They argue that it
should be easier to maintain the type of water chemistry found
over a natural reef by relying on an algal scrubber.
Also, algae remove the nitrogen from the water in order to build
tissue, while filter bacteria simply put it into a less toxic
form. The excess nitrogen can be removed completely by periodic
algae harvests, while dissolved nitrogen in the form of nitrate is
not as easy to remove. Adey and Loveland claim that their methods
can bring levels of DIN down to a few hundredths of a ppm, far
below (in their opinion) the levels reachable with other methods.
A related argument in favor of algal scrubbers is that stability
in natural ecosystems seems to come from locking up nutrients in
biomass, not in allowing it to be free in the environment. An
algal scrubber does precisely this, while a bacterial filter
converts it to free nitrate dissolved in the water.
A final reason to use an algal scrubber according to Adey and
Loveland is that many other kinds of filtration (including protein
skimmers) remove plankton from the water. An algal filter
naturally does not do this, and can actually provide a refuge for
some forms of plankton. The importance of this effect is,
however, a matter of some debate.
As compelling as some find the above arguments in theory, there
seem to be serious problems with algal scrubbing in practice.
Many attempts by public aquaria at implementing reef tanks using
only algal scrubbing have been failures. In particular, it seems
difficult to find successful long term success with Scleractinia
(stony corals) in such tanks, and those success stories which can
be found are quite difficult to verify and often contradicted by
others.
Various public and private aquaria have used algae scrubber
filters on their reef aquaria, with disastrous results. The
microcosm at the Smithsonain Institution has yet to keep
scleractinia alive for more than a year. While Dr. Adey has stated
how well corals grow in this system, those viewing the system have
failed to find these corals. In an interview with Jill Johnson,
one of the techs responsible for the Smithsonian tank, she stated
to Frank M. Greco that frequent collecting trips were needed to
keep the system stocked with live scleractinia.
The Pittsburgh AquaZoo also has a "reef" tank based on Dr. Adey's
algal scrubbers. This tank is nothing more than a pile of rocks
covered with filimentous green algae, and the water is QUITE
yellow (as is the Smithsonian tank) from the presence of dissolved
organics (ORP readings have been around 165). As with the
Smithsonian tank, scleractinia do not survive longer than a few
months. The same applies to soft corals as well. When I (Frank M.
Greco) saw this tank on May 3, 1993, there were NO living corals
to be found even though a collecting trip to Belize was made
several months earlier and 81 pieces of living scleractinia were
brought back. There were, however, two piles of dead Atlantic
scleractinia: one right behind the tank and the other in the
greenhouse housing the algal scrubbers.
The Carnegie Science Museum (Pittsburgh, PA) also uses an algal
scrubber system, but with significant modifications. This tank
looks the best of the three. There are several species of hardy
Scleractinia and soft corals that are doing quite well. The water
is clear (a bit cloudy). The major differences between this system
and the other two is the use of carbon, a small, barely
functioning algal scrubber, about 1000 lbs. of excellent quality
live rock (Florida), water changes, and the addition of Sr and Ca.
The last system I know of that uses an algal scrubber is the Great
Barrier Reef Microcosm in Townsville, Australia. As of this
writing, the system is not maintaining live Scleractinia, and
frequent collecting trips are needed in order to replenish the
exhibit. It should also be noted here that while Dr. Adey has
claimed in his book Dynamic Aquaria that corals have spawned in
this system, what he doesn't mention is that the corals which
spawned were collected only months before the known spawning
season. From these few examples, it should be clear that algal
scrubbers are NOT to be used in systems containing live
scleractinia.
Possible reasons why algal scrubbers seem to fall short center
around the observation that it seems difficult to control hair
algae growth in scrubbed aquaria. Hobbyists have for many years
seen their stony corals slowly pushed back off of their skeleton
and killed by encroaching algaes, and much effort in the hobby has
been devoted to controlling this growth. Only with strict control
of algaes does coral survival seem possible. Most or all reefs
with algal scrubbers seem to have heavy algal growth in the tank
as well, which the experience of the hobby suggests is
incompatible with stony coral survival.
The main method used by hobbyists to restrict algal growth is to
reduce nutrient availability; in fact, the claim that other
methods cannot reach the same low levels of DIN achieved by algal
scrubbing is probably not true. Advanced hobbyists are beginning
to use better tests, such as HACH's low level nitrate test, and
are finding that they can achieve nitrate levels below 0.02 ppm.
Berlin methods seem particularly able to reach these levels, which
are comparable to that on natural coral reefs.
If low nutrient levels can be achieved by both methods, then why
is algal growth a much greater problem with scrubber methods? The
answer is not known, but there are two factors which probably
contribute.
First, the discussion so far has mentioned only inorganic
nitrogen. Algaes seem to release much of the inorganic nitrogen
which they take up in the form of dissolved organic compounds
(DON), which can also be later utilized by algaes. The very low
levels of DIN measured in scrubbed tanks may mask the very high
levels of DON which persist, providing nutrients for strong algal
growth. This is borne out by many reports that the water in
scrubbed tanks often has a pronounced yellow cast, characteristic
of dissolved organic compounds. Since the water over natural
reefs is very low in DON, high levels may be directly harmful to
many corals, in addition to promoting uncontrolled algal growth.
Another possible effect of algal scrubbing is more subtle. Algal
growth is never completely halted in any marine tank, merely
reduced to the point where macro- and micrograzers can keep them
in close check. The net rate of new growth depends not only on
the availability of nutrients, but also on the amount of existing
algal growth releasing free-floating cells into the water to
colonize new sites. Even if the rate of growth of individual
algal colonies is equal, a scrubbed tank has a growth of algae in
the scrubber much larger than a reef tank with little algal growth
anywhere in the system. This possibility suggests that the
presence of the scrubber itself and not merely high levels of DON
is an obstacle to the successful long-term maintenance of stony
corals.
The weight of evidence at this point seems to be against the use
of algal scrubbing in reef tanks, and the method should be
considered to be highly experimental. Beginners particularly are
advised to avoid this technique until they have considerably more
experience with reefkeeping. The advanced aquarist may well wish
to experiment with this interesting and controversial method, but
it would be unwise to risk the lives of an entire reef tank full
of coral. Such experiments should progress slowly, beginning with
the most hardy of inhabitants. Many of the objections center on
stony coral survival, and it is possible that scrubbed tanks with
fish and hardy invertebrates may do quite well.
2.10 Live Sand
Of relatively recent interest in the hobby is the use of "live sand".
Live sand consist of small grain (0.5mm-1.0mm) coral sand that is
populated with crustations and bacteria. It is normally used at a
rate of 10lbs per square foot of bottom area - which yields about a
1" deep covering. Variations from 1/8" to 3"s of covering have been
reported.
If you decide to have a live sand substrate bottom, you should
include several creatures that will turn-over, or otherwise, move
the sand around. Recommendations include: Sea Cucumbers, Brittle
Starfish, Serpant Starfish, Golden Headed Sleeper Gobies, Yellow
Jawfish, Watchman Gobies, and other detrivoirs. A mix of the above
is recommended, since each creature moves the sand around differently.
Live sand has a reputation of eliminating the final traces of nitrates
in otherwise well run tanks. It also provides an environment for
additional bio-diversity in the tank. Additionally, some feel that
the chemical balance and stability of a tank's water is improved when
live sand is present.
* Note that live sand usage should still be considered experimental.
* Usage is dependant upon have the sand sifted and otherwise moved
* around to prevent detritus from accumulating. Many people have reported
* problems keeping their turn-over creatures alive for long periods
* of time. Some have not seen the reported nitrate reductions. Keep
* in mind that many reef tanks have operated for years without a substrate
* and have no detectable nitrate concentrations.
3.0 Lights
*3.1 General Discussion
A rough "rule of thumb" is 4 Watts/gallon with successful tanks
using from 1.5 - 6 Watts/gallon.
1) Fluorescent fine (some prefer) for shallow (<20") tanks. Use
mix of bulbs (50-50, 03s, etc.)
2) Metal Halide (MH) required for deeper tanks.
3) Mercury Vapor, Halogen, HPS, etc. - avoid, wrong spectral
output.
*3.2 Detail Discussion
For most aquarium lighting applications, the bottom line is
getting the needed intensity and spectrum of light at the lowest
cost while remaining within aesthetic limits.
A lighting analysis is now presented. Everyone has their own sets
of numbers they would plug in here, for now lets assume the
following for comparison. Many will debate specifics found below.
Feel free to substitute your own numbers, but the methodology is
sound.
Bulb cost and performance:
NO lumens per lamp = 2600 (Phillips F40D daylight, initial)
NO watts per lamp = 40 (ditto)
NO cost per lamp = ~$20 (from memory, DLS actinic day)
VHO lumens per lamp = 5940 (Phillips F48T12/D/VHO daylight, initial
)
VHO watts per lamp = 110 (ditto)
VHO cost per lamp = ~$30 (ditto)
MH lumens per lamp = 36000 (Philips MH400/U, initial)
MH watts per lamp = 400 (ditto)
MH cost per lamp = ~$70 (from memory, Venture 5200K)
operate lamps 12 hours/day
replace lamps once per year
electricity cost = $.09 / KWH (your mileage may vary)
Annual cost per lumen:
cost = ( cost-per-lamp / lumens-per-lamp )
+ ( watts-per-lamp / lumens-per-lamp ) * 12 * 365 * .09 / 1000
NO cost = .0077 + .0061 = .0138 dollars per year per lumen
VHO cost = .0051 + .0073 = .0124 dollars per year per lumen
MH cost = .0019 + .0044 = .0063 dollars per year per lumen
Basically, in fluorescents, the VHO lamps give a higher operating
cost but a lower replacement cost for the same total amount of
light. But it's close, and you should plug in your own numbers to
see what's best for you. If you replace lamps more frequently
then VHO is better, if you pay more for power, NO is better.
There is a greater variety of lamps available for NO than VHO.
OTOH, it seems that NO lamps can be operated at VHO power levels,
with a somewhat shortened lifetime (the higher replacement
frequency is offset by lower lamp cost), so this may not be an
issue.
The initial installation cost (basically the ballast cost) is
higher for VHO, even in terms of per-lumen, but this is a pretty
small part of the total cost of the lighting system over the
years.
NO requires more lamps for a given total light intensity, so you
may not be able to fit enough NO bulbs in your hood if you need a
lot of light.
MH seems to be a winner in both replacement and operating costs,
but there are a couple of caveats. The math ignores the effect of
the ballasts on power consumption, whereas I've measured
fluorescent power consumption as less than the lamp wattage (even
on conventional transformer ballasts) and MH power consumption as
slightly higher than the lamp wattage. The other caveat is just
the EXTREMELY limited choice of spectrums for MH, which is why few
people use MH without any fluorescent.
MH vs fluorescent also gets into the aesthetic and biological
considerations. Water surface ripples causing light ripples in
the aquarium and room are pronounced with MH lighting. Many
people appreciate this effect. Some (e.g. Julian Sprung) feel the
variation in light intensity is actually important for some
photosynthetic organisms.
Many people are under the impression MH runs hot, whereas
fluorescent doesn't. In reality, the efficiencies are similar,
with MH producing slightly LESS heat than the equivalent
fluorescent. The difference is MH dumps all the heat in a small
space so the local temperature rise is greater. But if you want
to try to get rid of the heat it's actually easier to do it if the
heat is concentrated in one spot, since its easier to get rid of a
small amount of very hot air than a very large amount of warm air.
A separate issue, so far only applicable to fluorescent, is the
selection of a conventional ballast vs an electronic one. There is
no doubt the electronic ones are more expensive to purchase, but
the savings in electricity offset the high initial cost in a year
or so. Also, if heat production is an issue, the electronic
ballasts are to be favored. The Icecap VHO electronic ballast is
widely advertised, however its advertised claims are also
frequently questioned. Advance makes a series of NO electronic
ballasts.
There are yet two more issues, for which there are a lot of
questions and too few answers. Specifically, the short term
flicker in light intensity, and radiated electromagnetic fields.
Fluorescent lamps on conventional ballasts flicker at 120 Hz,
which is above the human visual response, so we don't see it
(actually, the flicker is both in intensity and spectrum). But
that doesn't mean other creatures can't see it, or whether they
benefit or are disadvantaged by it. Electronic ballasts cause
flicker at ~30 KHz; it is seriously doubtful that any creature can
detect this, so it would appear constant.
The flicker doesn't have to be visible to have an effect: it
causes any movement to appear strobed, and this may affect the
feeding efficiency of visual hunters.
The fields issue is even more obscure. At least many
cartilaginous fish (sharks, rays, etc) are known to be extremely
sensitive to electric fields, and many crustaceans are sensitive
to magnetic fields (crabs with pieces of magnetite in internal
sensory organs). Fluorescent lamps, with the large area they
cover, tend to radiate (using the term pretty loosely) fairly
strongly, but MH, and the wiring, and the ballasts can radiate
too. It's unknown on how significant this could be in an aquarium
(but its known sharks preferentially attack undersea cables
because of the fields, so there is at least indirect evidence its
an issue worth some thought).
BTW, a grounding device reduces the level of induced voltages in
the tank, but this is achieved at the expense of increased induced
current, so its effect (if any) may depend on the species. Also,
note if you have a titanium coil chiller on the tank, it is probably
already grounded through the chiller, and an additional ground may in
fact increase the electric current. This should not be an issue
with epoxy or ceramic coated chiller coils.
*3.3 Lighting Data (whole section new, and copyrighted!)
==========================================================================
FILE|WATTS|MANUFACTURER|DESCRIPTION |HOURS |TYPE |
T1 400 IWASAKI 6500K M/H
T2 20 LIGHTSOURCE UVB FL
T3 20 LIGHTSOURCE UVB WITH FILTER FL
T4 400 VENTURE 4000K M/H
T5 400 VENTURE 4000K WITH FILTER M/H
T6 400 SYLVANIA 4000K 2400 HOURS M/H
T7 60 CHROMALUX TUNGSTEN
T8 40 CORALIFE 50/50 FL
T9 40 ACTINIC SUN FL
T10 40 PHILLIPS ACTINIC 03 3650 HOURS FL
T11 40 PHILLIPS ACTINIC 03 FL
T12 40 RAINBOW PRIMETINIC FL
T13 40 RAINBOW FLORA_GLOW FL
T14 40 RAINBOW BIO_LUME FL
T15 40 TRITON 3650 HOURS FL
T16 40 DURALIFE POWER TWIST FL
T17 40 HAMILTON SUPER ACTINIC 3650 HOURS FL
T18 40 PKILLIPS ULTRALUME 3650 HOURS FL
T19 40 PERFECTO PERFECTALIGHT FL
T20 40 SYLVANIA 350EL BLACKLIGHT 3650 HOURS FL
T21 40 SYLVANIA 350EL BLACKLIGHT FL
nm T1 T2 T3 T4 T5 T6 T7 T8 T9
280 0 0
290 0.00369 0
300 0.01136 0
310 0.0173 0
320 0.01326 0
330 0.00725 0
340 0.00366 0
350 0.00928 0.00126 0 0.00173 0 0.01344 0.00156 0 0
360 0.01185 0.00155 0 0.03944 0 0.07642 0.00071 0.00012 0.00011
370 0.02 0.00199 0 0.03428 0 0.07363 0.00166 0.00115 0.00104
380 0.03036 0.0007 0 0.0043 0 0.03063 0.00361 0.00086 0.00075
390 0.0446 0.00084 0 0.01287 0 0.05199 0.00574 0.00422 0.00329
400 0.07903 0.00544 0.0014 0.07214 0.01949 0.14805 0.01098 0.02255 0.01686
410 0.08931 0.0058 0.00188 0.06103 0.02356 0.1331 0.01644 0.05968 0.04407
420 0.16201 0.00126 0.00076 0.01713 0.01747 0.06811 0.02291 0.08731 0.06047
430 0.09997 0.01352 0.01175 0.13073 0.13383 0.2202 0.02654 0.09023 0.06469
440 0.08765 0.02331 0.02023 0.1601 0.1598 0.2264 0.03179 0.0736 0.05465
450 0.07976 0.00053 0.00041 0.01077 0.01184 0.04449 0.03795 0.02631 0.02099
460 0.12665 0.00078 0.00072 0.00687 0.00716 0.03796 0.04864 0.01588 0.01347
470 0.15064 0.00074 0.00069 0.01622 0.02078 0.07935 0.06293 0.01061 0.00931
480 0.16282 0.00071 0.00066 0.01501 0.01751 0.07474 0.08342 0.01361 0.0122
490 0.262 0.00081 0.00075 0.01746 0.01798 0.07031 0.10565 0.02889 0.02518
500 0.1875 0.00074 0.00069 0.01715 0.01926 0.07363 0.11878 0.01326 0.01125
510 0.1742 0.03241 0.03973 0.12924 0.11684 0.00561 0.00456
520 0.1746 0.01067 0.01085 0.06063 0.11877 0.00424 0.00337
530 0.1903 0.01495 0.01622 0.06525 0.11566 0.00658 0.00568
540 0.2163 0.2472 0.2453 0.3389 0.17133 0.0945 0.08678
550 0.2249 0.3589 0.3569 0.4931 0.2222 0.10093 0.08811
560 0.1535 0.01939 0.02075 0.07519 0.2276 0.00777 0.00829
570 0.1721 0.15115 0.15653 0.2859 0.11034 0.00485 0.00444
580 0.2015 0.4783 0.47 0.6035 0.04333 0.02203 0.0205
590 0.11089 0.1499 0.10326 0.4279 0.04889 0.02291 0.02103
600 0.13418 0.015 0.01253 0.07882 0.15686 0.01332 0.01218
610 0.12794 0.01226 0.01103 0.0517 0.2926 0.07374 0.06906
620 0.14258 0.02842 0.0302 0.10766 0.3906 0.04382 0.03969
630 0.13358 0.03349 0.03673 0.10084 0.4227 0.02397 0.02217
640 0.11311 0.014 0.01398 0.05127 0.4511 0.00603 0.00571
650 0.09402 0.01115 0.01077 0.04064 0.4742 0.00692 0.00652
660 0.10513 0.01143 0.01088 0.04971 0.4899 0.00584 0.00544
670 0.085 0.01551 0.01315 0.08427 0.4922 0.00403 0.00386
680 0.08657 0.01111 0.01079 0.03203 0.4808 0.0037 0.00358
690 0.09202 0.01929 0.01898 0.03834 0.4944 0.00411 0.00377
700 0.08359 0.00975 0.01033 0.03056 0.5355 0.00286 0.00277
710 0.04801 0.01305 0.01273 0.02949 0.5522 0.00911 0.00917
720 0.05045 0.01045 0.01025 0.03059 0.5485 0.00149 0.0014
730 0.04745 0.00957 0.00941 0.0182 0.4476 0.00042 0.0004
740 0.04609 0.00985 0.00964 0.02177 0.2395 0.00041 0.00039
750 0.04023 0.00983 0.00959 0.01954 0.2498 0.00037 0.00035
nm T10 T11 T12 T13 T14 T15 T16 T17 T18
350 0 0 0.0001 0 0 0 0 0 0.00011
360 0 0 0.00167 0 0 0 0.00144 0 0.00147
370 0 0.00016 0.00087 0.00119 0.00126 0.00145 0.00196 0 0.00133
380 0.00011 0.0007 0.00063 0.00027 0.00017 0.00023 0.00145 0.00011 0.0007
390 0.00403 0.00563 0.00399 0.00033 0.00012 0.00018 0.0021 0.00155 0.00066
400 0.01468 0.0379 0.02569 0.00377 0.00299 0.0037 0.00745 0.02094 0.00546
410 0.04403 0.12285 0.07521 0.00446 0.00432 0.00611 0.00952 0.08984 0.0083
420 0.06681 0.1955 0.12078 0.00138 0.00651 0.00983 0.0078 0.15751 0.00904
430 0.06231 0.1714 0.13584 0.01281 0.03371 0.03597 0.02406 0.14212 0.03191
440 0.04237 0.10573 0.1221 0.0229 0.0599 0.05814 0.03307 0.08825 0.04797
450 0.01287 0.03535 0.05784 0.00225 0.04818 0.04703 0.0128 0.03013 0.02376
460 0.00567 0.01538 0.03935 0.00271 0.04462 0.05381 0.01496 0.01326 0.02429
470 0.00268 0.00698 0.02608 0.00332 0.03433 0.0541 0.01834 0.0061 0.02294
480 0.00125 0.00319 0.02679 0.00396 0.02981 0.05097 0.02108 0.00287 0.03173
490 0.00082 0.00195 0.05095 0.00486 0.03909 0.04972 0.02354 0.00178 0.05773
500 0.00062 0.00051 0.02319 0.00537 0.02092 0.03006 0.02579 0.00056 0.02643
510 0.00037 0.00073 0.00728 0.00672 0.01013 0.01802 0.02974 0.00079 0.01024
520 0.0003 0.00056 0.00496 0.00985 0.00732 0.01111 0.03445 0.00064 0.0078
530 0.00027 0.00049 0.00645 0.016 0.00668 0.01075 0.03592 0.00056 0.013
540 0.00623 0.01053 0.13192 0.03586 0.07958 0.0697 0.04315 0.00846 0.1921
550 0.01079 0.0185 0.1251 0.05488 0.07655 0.06983 0.04723 0.01463 0.1743
560 0.00028 0.00038 0.01025 0.04627 0.00731 0.0088 0.02902 0.00035 0.02394
570 0.00061 0.00085 0.00549 0.05201 0.00444 0.00586 0.02876 0.00069 0.01534
580 0.00314 0.00569 0.03686 0.0556 0.02172 0.0227 0.032 0.00446 0.04439
590 0.00039 0.00047 0.03892 0.04418 0.01716 0.02913 0.02544 0.00044 0.04907
600 0.00013 0.00051 0.01518 0.04409 0.00375 0.02508 0.0284 0.00036 0.03261
610 0.00126 0.00136 0.09569 0.04722 0.01159 0.16014 0.03433 0.00087 0.14292
620 0.0009 0.0015 0.06356 0.05247 0.04658 0.07106 0.03533 0.0013 0.08503
630 0.00057 0.00087 0.0269 0.06004 0.06313 0.03852 0.03461 0.00084 0.04806
640 0.0003 0.0006 0.00674 0.05213 0.05384 0.0087 0.03259 0.00043 0.01323
650 0.00025 0.00047 0.00797 0.07652 0.1192 0.01039 0.0305 0.00036 0.01485
660 0.00026 0.00049 0.00564 0.10016 0.1775 0.00799 0.02782 0.00039 0.01222
670 0.00023 0.00043 0.00554 0.04559 0.06493 0.00461 0.02474 0.00035 0.00851
680 0.0002 0.00039 0.00499 0.02232 0.01908 0.00396 0.02155 0.00031 0.00761
690 0.00032 0.00056 0.00425 0.01701 0.00976 0.00639 0.01861 0.00047 0.00787
700 0.00022 0.00041 0.00348 0.01193 0.00434 0.00551 0.01536 0.00032 0.00583
710 0.00041 0.00077 0.01145 0.00964 0.00302 0.01905 0.01322 0.0006 0.01719
720 0.00022 0.00049 0.00167 0.00712 0.0013 0.00286 0.01038 0.00034 0.00305
730 0 0.00013 0.00044 0.00546 0.00072 0.00068 0.00827 0 0.00054
740 0 0.00012 0.00045 0.0044 0.00059 0.00075 0.00685 0 0.00098
750 0 0.00013 0.0004 0.00352 0.00045 0.00071 0.00559 0 0.00093
nm T19 T20 T21
300 0
310 0.01441
320 0.00473
330 0.01484
340 0.03041
350 0 0.01513 0.02693
360 0.0001 0.01831 0.03403
370 0.00144 0.01491 0.02582
380 0.00097 0.00948 0.01617
390 0.00474 0.0052 0.00903
400 0.00806 0.00633 0.00942
410 0.01157 0.00532 0.00778
420 0.01243 0.00154 0.00258
430 0.02928 0.01093 0.01555
440 0.0403 0.01854 0.02698
450 0.0223 0.00053 0.00163
460 0.0258 0.00069 0.00137
470 0.02929 0.00061 0.00124
480 0.03084 0.00057 0.00072
490 0.03039 0.00076 0.00119
500 0.02779 0.00063 0.00101
510 0.02431 0.00037 0.0007
520 0.02064 0.00029 0.00056
530 0.01756 0.00028 0.00048
540 0.02217 0.00924 0.00974
550 0.02535 0.01594 0.01769
560 0.00816 0.00029 0.00033
570 0.00725 0.00062 0.00081
580 0.0119 0.00497 0.00639
590 0.00888 0.00044 0.00042
600 0.00953 0.00035 0.00037
610 0.05257 0.00111 0.00114
620 0.03046 0.00129 0.00145
630 0.03244 0.00082 0.00089
640 0.02281 0.00047 0.00047
650 0.04607 0.00035 0.00037
660 0.06831 0.00039 0.00038
670 0.02469 0.00033 0.00034
680 0.00813 0.0003 0.0003
690 0.00567 0.00046 0.00047
700 0.00362 0.00031 0.00032
710 0.0071 0.00062
720 0.00146 0.00033
730 0.00059 0
740 0.00052 0
750 0.00045 0
ALL DATA CONTAINED WITHIN IS COPTRIGHT 1994 BY FRANK M. GRECO
(phrank2139@aol.com) AND BRUCE ROBERTS (baldbruce@aol.com) AND TO BE USED
ONLY WITH PERMISSION OF ONE OR BOTH OF THESE PEOPLE.
=========================================================================
4.0 Cost Estimates
Here is a rough estimate of what setting up a reef tank may cost.
Two cases are included: a 20g micro-reef and a 70g mini-reef. The
estimates show the min and max for most of the common pieces of
equipment. The estimates assume a standard type of filtration
that is popular today. If a different setup is used, the price
could be more or less. The equipment includes a tank with some
sort of siphon/drain to a sump and then a return pump back to the
tank. A protein skimmer is installed in the sump. This setup is
similar to a typical wet/dry trickle filter except there is no
trickle section with media. This allows the use of simpler, less
expensive sump although a commercial W/D without media could be
used. A trickle media could be utilized at greater cost although
many reefkeepers think it is unnecessary. Keep in mind that
prices sometimes vary geographically. Also, availability may
vary. For example, reasonable Florida live rock may soon no
longer be available (at least not for $2-4/lb).
The estimates include the cost of the initial set-up. There is
also a section on ongoing costs. The ongoing cost will vary
greatly, especially considering that you will stock your tank
gradually. Keep in mind that you always end up spending more than
you think you will. If you set up a reef, you will end up stopping
at the hardware store and/or aquarium store for timers, extensions
cords, GFIs (a must!), buckets, hoses, and books, don't for forget
books. You should read a few books on reefkeeping before even
planning your setup. An extra hundred bucks or three _is_ going
to leak out of your wallet whether you plan on it or not.
Another factor is that more advanced equipment may translate into
less or easier maintenance. You should keep in mind that if you
go with inferior equipment, maintaining the tank will be more
work. More expense will mean more automated equipment and less
work. Also, some varieties of inverts require more exacting
condition, more light, etc. Plan your purchases so that the stock
you buy has a chance of surviving with the equipment you are
using. If you have a bare minimum system, stick hardy items like
soft-corals, polyps, mushrooms, etc.
The minimum included is close to rock-bottom as far as an
acceptable systems goes. It assumes that you are DIYing much of
the equipment as cheaply as possible. The maximum in the estimate
is in some areas a little extravagant but not unreasonable. A good
system that is not extravagant could be put together for somewhere
in between the two extremes. Perhaps, for 1.25 to 2 times the
minimum, you would have a very nice system. Some areas are easier
to cut-corners on than others and some of the initial cost may be
incremental, like buying test kits as needed. Also, you may have
some of the equipment already from previous set-ups or be buying
it used. Seek out the advice of an experienced reefkeeper when
planning and pricing your system.
-------------------------------Micro-Reef(20g)-------------------------------
Tank $ 20/ 140 Glass/
Acrylic.
Stand 0/ 250 Sturdy piece of furniture/
Fancy acrylic stand.
Lights 100/ 300 DIY 60W fluorescent/
70W or 150W MH hood or pendant.
Main Pump 20/ 60 Large powerhead/
Hobby pump.
Sump 10/ 120 A plastic storage container from the
hardware store / A small commercial W/D
without media. (A nice DIY acrylic
sump can be built for about $40.)
Skimmer 60/ 220 DIY skimmer, power head, air pump/
Small commercial venturi unit with
integral pump.
Plumbing 30/ 100 DIY overflow and misc pipes, etc/
Drilled tank or commercial overflow box
plus misc pipes, etc.
Live-Rock 140/ 400 35lb case of Fla rock plus shipping/
30lbs of Pacific rock plus shipping.
Water Treatment 100/ 600 DIY mixed-bed DI with carbon prefilter/
TFC RO unit with DI postfilter and
automated top-off.
Test Kits 100/ 500 A SW combo kit plus and Alk and Ca test/
Most of the Lamotte and/or Hach kits
you think you might need.
Salt 10/ 20 One 50g bag, price varies.
Accessories 20/ 200 There are a variety of gadgets you could
get. You might want to start with a
net or two and maybe a pair of tongs.
---- ----
Setup Total $ 610 2910
--------------------------------Mini-Reef(70g)-------------------------------
Tank $ 140/ 350 Glass/
Acrylic.
Stand 100/ 500 Cheap wood or iron stand/
p Fancy acrylic stand.
Lights 200/ 600 DIY 160W fluorescent/
2x150-175 MH hood (possibly with Actinics).
Main Pump 80/ 140 400-600gph, price varies with brand.
Sump 10/ 200 A plastic storage container from the
hardware store / a commercial W/D
without media. A nice DIY acrylic
sump can be built for about $50.
Skimmer 80/ 450 A DIY skimmer,powerhead,air pump/
A large commercial venturi unit
with a large pump driving it.
Plumbing 50/ 150 DIY overflow and misc pipes, etc/
Drilled tank or commercial overflow box
plus misc pipes, etc.
Live-Rock 460/1200 140lbs Fla rock plus shipping/
110lbs Pacific rock plus shipping.
Water Treatment 100/ 600 DIY mixed-bed DI with carbon prefilter/
TFC RO unit with mixed-bed DI
postfilter and automated top-off.
Test Kits 100/ 500 A SW combo kit plus and Alk and Ca test/
Most of the Lamotte and/or Hach kits
you think you might need.
Salt 20/ 40 Two 50g bags, price varies.
Accessories 40/ 500 There are a variety of gadgets you could
get. You might want to start with a
net or two and maybe a pair of tongs.
You could get wave-makers, circulation
pumps and lots of other do-dads.
Chiller 0/ 600 Don't use a chiller, live somewhere cool,
keep the tank in the basement, or an
adequately air-conditioned room/
A commercial chiller.
---- ----
Setup-Total 1380 5830
--------------------------------Ongoing Costs---------------------------------
Additives- Most reefkeepers believe that some additives are necessary.
At minimum, a buffer compound is needed to maintain the alkalinity.
Also, some Calcium supplement such as Kalkwasser or Cacl2 should
be used. A few trace additives like Strontium and Iodine/Iodide
should also be added. The initial supply of these products will
be around $50. The ongoing rate will vary depending on the size
of the tank.
Water Purifier- If you go with a DI system, you will have to replace
and/or recharge resin. An RO system will require periodic
replacement of the membrane. In the long run, maintenance
of the RO is likely cheaper.
Test Kits Reagents- You will need replace reagents for the tests kits.
Also, the minimum given above is may not be adequate. The
typical SW combo kits are not of low enough range for reef work.
They will only be of use during the first few weeks of
cycling/curing. That estimate assume that you will acquire
the better tests over time or have access to someone else's
expensive tests should you need to diagnose a problem.
Electricity- You will need it to run the pumps and lights. It won't be
insignificant. Electric costs vary. Check the KW cost
on your electric bill. Add up wattage of all the equipment you
are using, pumps 24hrs/day, lights 12hrs/day. Calculate what
the electricity will cost. Don't forget cooling, in many areas,
you will need either a chiller or will have to air-condition the
room where the reef is kept. The lights will generate heat. At
minimum, your AC bill will also go up accordingly. Electricity
mini-reef system could easily be a couple hundred bucks a year.
Water- In some areas, water is expensive. RO units waste several times
what they produce in water. This could add a little more expense.
Salt- You may want to do water changes in which case you will
* eventually need more salt. Salt mixes run $10-$25 per 50 gallon
* mix.
Lights- Fluorescent tubes and MH bulbs wear out. Fluorescent tubes
are usually okay for nine months to a year before spectrum
shifts and/output reduced significantly. Some tubes, like
actinics, may need replacement as frequently as every six
months. Replacement MH bulbs is recommended about every one to
two years (depending upon spectral shift and output degradation).
Add up the cost of your tubes and figure in the
replacement cost based on the estimated lifetime.
Stocking- This can really vary. You probably shouldn't have more
than a couple fish in the micro-reef and not more than
a handful in the mini-reef. The typical fish suitable
for a reef will be from $10(small goby or blenny) to
$30(small angel or tang). You could spend $300 on one purple
tang though. Pieces of coral, decorative rocks, giant
clams and other sessile inverts start at around $20 a piece
and go to many hundreds a piece. Snails range from about
$1/each to about $8/each and are recommended for controlling
algae. Other motive inverts likes shrimp range from about
$10 to $30.
You probably should start with the snails as soon as the
live rock is in the tank. You don't have to have any fish
if you don't want any. You don't have to have inverts either
although that is probably why you set up a reef tank. Just
quality live-rock is very of nice to look at but sooner or
later you will likely want something else in your tank. The
invert stocking will be very incremental and should be.
It is not heathly to add a lot of stock at once. You can
spread you stocking over up to several years. You could spend
anywhere from say $100 to $750 on the micro-reef and $200 to
$10,000 on the mini-reef.
=================== End of ReefKeepers FAQ Part 1 of 3 =======================
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