Search the FAQ Archives

3 - A - B - C - D - E - F - G - H - I - J - K - L - M
N - O - P - Q - R - S - T - U - V - W - X - Y - Z - Internet FAQ Archives

[FAQ] Aquaria: Disease, Algae and Snails

[ Usenet FAQs | Web FAQs | Documents | RFC Index | Houses ]
Archive-name: aquaria/general-faq/disease
Rec-aquaria-archive-name: general-faq/disease
Alt-aquaria-archive-name: general-faq/disease
Sci-aquaria-archive-name: general-faq/disease
Posting-Frequency: monthly

See reader questions & answers on this topic! - Help others by sharing your knowledge
*  This is only a text dump of part of the Aquaria FAQs.                *
*  The web "original" may be more current, is navigatable hypertext,    *
*  and contains enhanced content not available in this posted version!  *
*  or      *

                        FAQ: Diseases and other Plagues

     * Freshwater Diseases
          + Causes
          + Prevention
          + Diagnosis
          + Some Common Diseases: bad water quality, ich, fin rot,
            injuries, dropsy, hole-in-head disease, swim bladder
            disorders, parasites, and velvet.
     * Saltwater Diseases
     * Algae
     * Snails
                              FAQ: Fish Diseases
Contributed by Elaine Thompson


   The FAQs owe their existence to the contributors of the net, and as
   such it belongs to the readers of rec.aquaria and alt.aquaria.
   Articles with attributions are copyrighted by their original authors.
   Copies of the FAQs can be made freely, as long as it is distributed at
   no charge, and the disclaimers and the copyright notice are included.

  Q: Why is my fish sick and how do I prevent more illness?
   A: Probably 80-90% of diseases in captive fish can be prevented by
   avoiding stress. Stress weakens fishes' immune systems, leading to
   increased susceptibility to disease. Actually, diseases and pathogens
   are almost always present in tanks, but a healthy fish's immune system
   will prevent them from being a problem. Some of the most common
   stressors for captive fish are:
     * Poor water quality: measurable ammonia or nitrites, or very high
     * The water temperature is fluctuating more than 2 deg F/day
     * Incompatible species in the tank.
     * Too many fish in the tank (5 adult angelfish in 10g tank).
     * The tank is too small for the fish (foot long fish in 10g tank).
     * The water is too warm or too cold for the species (goldfish vs.
     * wrong pH for species (Discus vs. African cichlids)
     * pH fluctuations greater than 0.2 units/day.
     * Insufficient cover or hiding places present.
     * Wrong water hardness for the species (Discus vs. African
     * Insufficient oxygen in the water.
     * Improper fish nutrition (wrong food, foods not varied).
Keeping your tank free of disease

  Q: Do I need a quarantine tank for new fish?
   A: Quarantining new fish is a good habit for all aquaria, but is not
   absolutely necessary for success. Quarantining is simply keeping a
   fish in a separate tank for long enough to be certain that it is
   disease free. Many beginners do fine without a quarantine tank, and
   object to the cost of another setup. A quarantine tank does cost more,
   but if a hobbyist has hundreds of dollars invested in fish, it is
   cheaper to have a separate quarantine tank than to replace fish killed
   by a newly introduced disease. Also, many of us become attached to
   fish and do not want to expose our pets to diseases from newcomers, no
   matter what the cost.
   The purpose of quarantining is to avoid introducing new diseases to a
   stable system, and to be able to better observe new fish for signs of
   disease. A quarantine tank can also double as a hospital tank for sick
   fish. Hospital tanks are good because they lower the cost of using
   medicines and keep diseased fish separate from healthy ones.
   Quarantine is probably most important for saltwater tanks/reef systems
   because of the difficulty of treating diseases, or wild-caught
   freshwater fish because they are probably not disease-free.
   Quarantining itself can stress fish so be sure quarantine is as
   stress-free as possible.
   To set up a quarantine or hospital tank:
     * Keep an extra filter -- a sponge filter is ideal -- or piece of
       filter floss in an established tank, so that you don't have to
       keep the quarantine tank set up at all times. Some people choose
       instead to keep the filter going with guppies or danios (for
       freshwater) or mollies (for saltwater).
     * If you don't keep the tank running, use old tank water to fill the
       tank. So: old tank water + established filter = instant
       established tank.
     * Add a spare airpump and heater. If you haven't messed with the
       heater during storage, it should come to wherever you had it last
     * Consider using Amquel or equivalent when medicating the tank in
       case the biological filter bacteria are sensitive to the
       medication. Sick fish are especially susceptible to ammonia. (Note
       that ammonia which has been bound with Amquel still shows up on a
       nessler ammonia test. So, if you are planning on testing for
       ammonia in that tank, you need to use a salicylate ammonia test.)
     * For a hospital tank, do small, frequent water changes (even every
   If possible, quarantine all of your new fish for about three weeks.
   During that time, gradually acclimate the fish to your tank's
   parameters: hardness, pH, salinity, temperature, etc., and watch for
   and treat any signs of disease.
   Do not medicate quarantined fish ``just in case.'' Only treat evident,
   definitely identified diseases. Treating all quarantined fish with a
   bunch of medicines will just lead to weakened fish and antibiotic
   resistant bacteria.
   Once you are done with the quarantine, if you treated any especially
   nasty diseases, it is good to disinfect the tank and reestablish the
   filter. Chlorine bleach or strong saltwater (for freshwater) work
   well. Be sure all traces of bleach are rinsed off. Another good
   disinfectant is potassium permanganate (Jungle's Clear Water is one
   commercial way to get it).
   If you choose not to quarantine, do not add store water to your tank
   with the new fish (see the BEGINNER FAQ for acclimation ideas).
  Q: How about quarantining plants?
   A: Plants can carry diseases into a tank, too. It is a good idea to
   disinfect new plants if there were fish in the tank with them at the
   store. Refer to the PLANT FAQ for disinfection methods.
  Q: How do I avoid introducing diseases in the first place?
   A: Never buy sick fish from a store. Especially do not buy fish or
   plants from a tank if *any* fish in the tank shows any signs of
   disease or if there is medicine in the water (water is colored yellow,
   green, or blue). Store people may say the fish are fine, but if they
   were, why is the medicine in the tank? Also ask how long the fish have
   been in the store. New arrivals may be carrying diseases that have not
   shown up yet. It is better to wait a couple of weeks before purchasing
   the fish. If you must have a fish that just came in, be especially
   sure to quarantine it properly.
Diagnosis/common diseases or: How do I know the fish is sick?

   Most important: watch your fish and know what their normal behavior
   and appearance is. If you don't know what normal is, you can't know
   what sick is.
   Bad signs:
     * Clamped fins (fins are held abnormally close to body)
     * The fish refuses its usual food for more than 2 days.
     * There are visible spots, lesions, or white patches on the fish.
     * The fish gasps at the surface of the water.
     * The fish floats, sinks, whirls, or swims sideways.
     * The fish shimmies (moves from side to side without going forward).
     * A normally active fish is still.
     * A normally still fish is very active.
     * The fish suddenly bloats up, and it's not due to eggs or young.
     * The fish is scratching against tank decorations.
   I suggest setting up a fish medicine cabinet. It seems like fish
   always get sick when the store is closed.
     * Water quality test kits: pH, ammonia, nitrite, nitrate
     * Aquarium salt (NOT table salt. Most table salts contain additives
       to keep them from clumping. Kosher or rock salt is OK).
     * Malachite green/formalin ich remedy
     * Methylene blue
     * Chlorine bleach for disinfection
     * Maybe one antibiotic (Kaynamycin or Furanace)
     * Antibiotic-containing food
     * Copper remedy for parasites
   And for fish big enough to handle:
     * Q-tips
     * Malachite green or mercurochrome
Common diseases/problems or What's wrong with my fish?

  Bad water quality
   Fish are gasping at the surface, or very inactive, but there are not
   visible lesions when it first starts. Their fins may be clamped. Many
   fish of different species are affected, and possibly the whole tank.
   If the water has been bad for a while, the fish may have finrot, or
   streaks of blood in their fins.
     * If fish are gasping at the surface, or have purple gills: high
       ammonia or low dissolved O2 may be the problem; test ammonia,
       dissolved O2
     * If the main symptom is inactivity: test nitrites, pH, dissolved
       02, nitrates
   Depending on your test results, try the following:
          Change enough of the water to reduce ammonia levels to 1-2 ppm
          for freshwater or below 1 ppm for saltwater. If that means
          changing more than a third of the water, be sure the water you
          add is the same temperature, salinity, hardness and pH of the
          tank water. It is also okay to do multiple smaller water
          changes for a few days. Aerate, and make sure pH is at or below
          7.0 for freshwater tanks. In addition to or instead of changing
          water, you can also add a dose of AmQuel to give fish immediate
          relief. Find out why ammonia is present and correct the
          Change enough of the water to bring nitrites down to below 2
          ppm (as with ammonia, if this is a lot of water, match water
          parameters or do multiple water changes), add 1 tbsp/gallon
          salt (not all fish may tolerate this much -- start out with 1
          tsp), and add supplemental aeration. Find out why the nitrite
          levels are high and correct the problem.
          Change water and clean the filter. If your filter is dirty,
          there is more waste material present to break down into
          nitrate. Start feeding less and changing water more often.
   Low oxygen
          Run an airstone. If this helps a lot, the fish probably don't
          have enough oxygen in the water. Your tank may need cleaning,
          fewer fish, or additional water movement at the surface from a
          powerhead, airstone, or filter.
   Improper pH
          If pH is too low: make sure carbonate buffering is adequate --
          at least 5dKH. In general, adding baking soda at 1 tsp. per 30
          gal. raises dKH about 2 degrees. For a 10-20g tank that just
          needs the pH a little higher, try about a quarter teaspoonful.
          If that isn't enough, add up to a teaspoonful more. You can
          scale this up to 1 tsp/30 gal for larger tanks. If the pH is
          still too low and the KH is at least 5-6 dKH, clean the tank.
          For long-term buffering in saltwater and alkaline freshwater
          systems, add crushed coral. If pH is too high, pH down
          (phosphoric acid) can be added. Don't rely on this stuff,
          except in extreme situations like ammonia poisoning because it
          can cause excessive algal growth. To lower pH long-term, filter
          over peat, or use distilled or deionized water mixed with your
  Freshwater Ich
   Symptoms: Fish look like they have little white salt grains on them
   and may scratch against objects in the tank.
   White spot disease (Ichthyopthirius multifiliis) is caused by a
   protozoan with a life cycle that includes a free-living stage. Ich
   grows on a fish --> it falls off and attaches to gravel or tank glass
   --> it reproduces to MANY parasites --> these swarmers then attach to
   other fish. If the swarmers do not find a fish host, they die in about
   3 days (depending on the water temperature).
   Therefore, to treat it, medicine must be added to the display tank to
   kill free-living parasites. If fish are removed to quarantine,
   parasites living in the tank will escape the treatment -- unless ALL
   fish are removed for about a week in freshwater or three weeks in
   saltwater systems. In a reef tank, where invertebrates are sensitive
   to ich medications, removing the fish is the only option. Some people
   think that ich is probably dormant in most tanks. It is most often
   triggered by temperature fluctuations.
   Remedy: For most fish, use a medication with formalin and malachite
   green. These are the active ingredients in many ich medications at
   fish shops. Some products are Kordon's Rid Ich and Aquarium Products'
   Quick Cure. Just read the label and you may find others. Check for
   temperature fluctuations in the tank and fix them to avoid
   recurrences. Note that tetras can be a little sensitive to malachite
   green, so use it at half the dose.
   Use these products as directed (usually a daily dose) until all of the
   fish are spot-free. Then dose every three days for a total of four
   more doses. This will kill any free-swimming parasites as they hatch
   out of cysts.
   Another remedy is to raise the tank temperature to about 90 deg F and
   add 1 tsp/gallon salt to the water. Not all fish tolerate this.
   Finally, one can treat ich with a ``transfer method.'' Fish are moved
   daily into a different tank with clean, conditioned, warmed water.
   Parasites that came off of the fish are left behind in the tank. After
   moving the fish daily for a week, the fish (presumably cured) can be
   put back into the main tank. The disadvantage of this method is that
   it stresses both fish and fishkeeper.
  Fin rot
   Fishes' fins turn whitish and die back. Fin rot often follows damage
   or injury. It can also be caused by poor water quality.
   Remedy: First, fix the water and remove any fin-nipping fish. Change
   some water (25% is good) and add 1 tsp/gallon salt to promote healing.
   If bad water quality or an aggressive tankmate was the problem, that
   should be adequate. Healing will begin within a couple of days.
   If it worsens, decide first whether it's fungal or bacterial. Fungal
   finrot looks like clumps of cotton on the fins and usually follows
   injury. It is commonly seen in African cichlids or fish that have
   injured themselves against decorations. Bacterial finrot is whitish,
   but not cottony (unless it's columnaris), and can be contagious. The
   fish then need to be removed from the tank and medicated.
   Fungus: For fish large enough to handle, catch the fish, and dab
   malachite green directly on the fungus with a Q-tip. This is extremely
   effective. Repeat treatments may be necessary.
   For small fish, a commercial fungicide such as Maroxy may work. For
   severe infestations, try a bath in methylene blue (enough so you can
   barely see the fish) until the fungus turns blue or for 20 min. If you
   add methylene blue directly to a tank, you will kill plants and trash
   your biological filter.
   Bacterial: Antibiotic treatment in a quarantine tank. This is
   stressful for the fish, and doesn't always work, so be sure of what
   you are doing before you attempt it. If the fish is still eating, the
   best bet is an antibiotic food. Tetra makes one that works well --
   just buy the one for bacterial diseases and follow the directions on
   the can.
   If the fish is not eating, a bath treatment is necessary. A
   combination of Kaynamycin and Furanace usually works, especially for
   Columnaris. Again, treat in a separate tank and aerate heavily.
   Cichlids and other ``scrappy'' fish may sustain injuries that are
   severe enough to draw blood from fighting. Other fish may run into
   tank decorations, walls, or rocks.
   Larger fish can be netted and their injuries dabbed with mercurochrome
   (available at drug stores) or Betadine (iodine-based antibiotic also
   available at drug stores) to help prevent infection. Be sure to keep
   these chemicals off of the gills and eyes. For really small fish, put
   the affected fish in dilute methylene blue (pale blue) and 1
   tsp/gallon salt in a separate tank. If you want to keep the fish in
   the main tank just add salt, as methylene blue will trash your
   biological filter.
   Watch the fish to be sure injuries are healing cleanly, and repeat the
   mercurochrome dosage if necessary. If finrot or fungus sets in, see
   the above section on finrot.
   Fish swells up like a balloon and may show popeyes. It may recover
   with no treatment and may die despite it. The swelling is because the
   fish is absorbing water faster than it can eliminate it, and it can be
   caused by many different problems. High nitrates are one thing to
   check. Internal bacterial infections, including fish TB, are other
   possibilities. If there are no water quality problems, you may want to
   attempt antibiotic treatment in a separate tank.
  Head and Lateral Line Erosion (hole-in-head disease)
   This disease can affect discus, other cichlids, and many saltwater
   fish. The fish develops holes in it's head and sometimes along its
   lateral line. Causes are unclear but as in any disease, stress and
   poor water quality likely play a role. The Manual of Fish Health
   states that HLLE is probably due to nutritional deficiency, especially
   of vitamin C. Fish in planted tanks rarely get HLLE, which supports
   the nutrition idea, since fish can nibble on the plants and obtain
   extra nutrition. Untergasser also observes that the protozoan Hexamita
   can be found in the lesions. Untreated cases can eventually prove
   disfiguring or fatal.
   Remedy: First, make sure water quality is optimal and reduce stress.
   Stopping carbon filtration may help as it can remove nutrients from
   the water. Then feed a vitamin-enriched food, paying particular
   attention to vitamin C supplementation.
   For stubborn cases, some books suggest metronidazole (Flagyl) to
   eliminate Hexamita (a mildly pathogenic protozoan) from the lesions.
   Your mileage may vary with that one. Metrozole and Hex-a-mit are
   commercial medications with metronidazole.
  Swim bladder disorders
   Fish floats upside-down or sideways. This is particularly common in
   fancy goldfish because of their bizarre body shapes. Dry food eaten
   quickly swells up in the fish's intestine and keeps the fish from
   controlling its swim bladder properly.
   To help, feed the fish pre-soaked or gel-based foods. Green foods are
   also helpful; peas in particular.
   As with finrot, these disorders can also be caused by bacterial
   infection. Treatment is much the same. Use antibiotic food if the fish
   is eating, or add antibiotic to the water in a quarantine tank if the
   fish is too sick to eat.
  Large external parasites (as opposed to ich)
   Add a copper remedy to the tank and monitor it with a copper test kit.
   Also, Mardel's Maroxy works well. For anchor worms or leeches on pond
   fish, remove them from the affected fish with tweezers and swab the
   area with mercurochrome to prevent infection.
   Fish look like they have been finely dusted with flecks of gold. Fins
   may be clamped and the fish may shimmy.
   Treat with an anti-parasitic medication such as copper or
   formalin/malachite green.

   The Manual of Fish Health
   Dr. Chris Andrews, Adrian Exell and Dr. Neville Carrington.
   New Jersey: Tetra Press, 1988
   This is an outstanding book, and I highly recommend it to anyone who
   is interested in reading about fish disease.
   Handbook of Fish Diseases
   Dieter Untergasser
   Translation by Howard H. Hirschhorn
   T.F.H. Publications, Inc., 1989
   This is my second-choice disease book. It is very good, but some of
   the treatments may be difficult to obtain, and it goes into more
   detail than the average hobbyist needs (or wants) to know.
                              Saltwater Diseases
contributed by Thomas Sasala

Scientific vs. Common Disease Names

   Scientific Name
          Common Names
   Amyloodinium ocellateum
          Amyloodinium, Oodinium, Marine Velvet, Saltwater Ich
   Cryptocaryon irritans
          Cryptocaryon, White spot disease, Saltwater Ich
   Brookynella Hostillis
          Brooklynella, Clownfish disease Angelfish disease
   Mycobacteria marinum
          Fish TB
   Tubellarian worms
          Black Ich, Tang Disease
   Benedenia melleni
          Fish Flukes
   Argulus sp.
          Fish lice
   Ichthyosporidium hoferi
          Fungus Disease
          Head and lateral line erosion (HLLE)
   Lymphocystis virus
          Viral disease, Cauliflower disease
   Pseudomonas sp.
          Fin Rot, Red Spot Disease, Ulcers (Bacterial Disease)
   Vibrio anquillarium
          Vibrio, "Wipe Out"
Suggested Treatment

   Disease Name
   1(4) Black Ich
          Freshwater dip coupled with formalin bath
   2(4) Brookynella*
          Copper coupled with formalin bath
   3 Fin Rot
          Erythromycin, Neomycin
   4 Fish Lice
          Freshwater dip or Formalin bath
   4 Flukes
          Freshwater dip or Formalin bath
   5 HLLE
          ? - Better environment
   6 Intern. Parasites
          Medicated Food
   7 Cryptocaryon*
          Formalin bath (1/2 -1 hour) once every other day for a week.
   8 Ichthyosporidium
          None - better environment
   9 Lymphocystis
          (None - it should go away)
   10 Amyloodinium*
          Freshwater dip coupled with copper
   11 Microsporidian
          None - euthanasia
   12 Poisoning
          Massive water changes/move to an untainted environment
   13 Poor Diet
          Vary Diet; meet the requirements of the animal
   14 TB
          Kanamycin, Isoniazid
   15 Vibrio
          Erythromycin, Neomycin
   * Both tank and fish must be treated to erradicate the pest.
Symptom Verses Likely Disease

   x = positive sign
   p = possible sign

                    1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
  Black Spots       x   -   -   -   -   -   -   -   -   -   -   -   -   -   -
  Change in color   -   -   -   -   -   p   -   x   -   -   -   x   -   p   x
  Cloudy Eyes       -   -   -   x   -   -   p   -   -   p   -   x   -   -   -
  Distended Stomach -   -   -   -   -   p   -   -   -   -   -   -   -   -   p
  Erratic Swimming  -   -   -   -   -   p   -   -   -   -   x   x   -   -   p
  Emaciation        -   -   -   -   -   p   -   -   -   -   x   -   x   p   -
  Fin Erosion       -   -   x   -   -   -   -   -   -   -   -   -   -   p   p
  Gasping           -   -   -   x   -   -   p   -   -   p   -   x   -   -   -
  Gold/Brown Spots  -   -   -   -   -   -   -   -   -   x   -   -   -   -   -
  Lack of appetite  -   -   -   -   -   -   -   p   -   -   x   p   -   x   x
  Listless          -   -   -   p   -   -   p   x   -   p   p   x   -   x   x
  "Pop Eyes"        -   -   -   -   -   -   -   -   -   -   -   -   -   p   p
  Reddened Areas    -   -   x   -   -   -   -   -   -   -   -   -   -   x   x
  Rough Skin        -   -   -   -   -   -   x   x   -   x   -   -   -   -   -
  Rubbing           x   -   -   x   -   -   x   -   -   x   -   p   -   -   -
  Ulcers/holes      -   -   -   -   x   -   -   -   -   -   -   -   -   p   p
  Wormlike attach's -   -   -   x   -   -   -   -   -   -   -   -   -   -   -
  Warty growths     -   -   -   -   -   -   -   -   x   -   -   -   -   -   -
  White Patches     -   x   -   x   -   -   -   -   -   -   x   -   -   -   -
  White Spots (1mm) -   -   -   -   -   -   x   -   -   p   -   -   -   -   -

                                  FAQ: Algae
contributed by George Booth

   The following descriptions and control techniques are for common types
   of algae found in freshwater aquaria.

   The FAQs owe their existence to the contributors of the net, and as
   such it belongs to the readers of rec.aquaria and alt.aquaria.
   Articles with attributions are copyrighted by their original authors.
   Copies of the FAQs can be made freely, as long as it is distributed at
   no charge, and the disclaimers and the copyright notice are included.

     * Algae Types:
       Blue-green, brown, green water, film, spot, fuzz, hair, thread,
       staghorn and brush algae.
     * Prophylactics
     * Algae-Eating Fish:
       Mollies, Otocinclus, Plecostomus, Siamese Algae Eaters,

   There are two categories of algae of concern to aquarists: "good" and
   "bad". Good algae is present in small quantities, is indicative of
   good water quality and is easily kept in check by algae eating fish or
   simple removal during routine maintenance. This algae is a natural
   consequence of having a container of water with nutrients and a light
   Bad algae is either an indicator of bad water quality or is a type of
   algae that tends to overtake the tank and ruin the aesthetics the
   aquarist is trying to achieve. The label of "bad" is entirely
   subjective. For example, one type of green, hair-like algae is
   considered a plague by some American aquarists, yet is cultivated by
   European aquarists as a valuable addition to most tanks, serving as a
   dietary supplement for the fish.
Algae Types

  Blue-green, slime or smear algae
   Grows rapidly in blue-green, slimy sheets. Spreads rapidly over almost
   everything and usually indicates poor water quality. However,
   blue-green algae can fix nitrogen and may be seen in aquariums with
   extremely low nitrates. Sometimes seen in small quantities between the
   substrate and aquarium sides. Will smother and kill plants.
   This is actually cyanobacteria. It can be physically removed, but this
   is not a viable long term solution as the aquarium conditions are
   still favorable for it and it will return quickly. Treatment with 200
   mg of erythromycin phosphate per 10 gallons of water will usually
   eliminate blue-green algae but some experts feel it may also have
   adverse effects on the biological filter bed. If erythromycin is used
   for treatment, ammonia and nitrite levels should be carefully
  Brown algae
   Forms in soft brown clumpy patches. In the freshwater aquarium, these
   are usually diatoms. Usually indicates a lack of light or an excess of
   silicates. Increased light levels will usually make it disappear.
   Easily removed by wiping the glass or siphon vacuuming the affected
  Green water
   Green unicellular algae will sometimes reproduce so rapidly that the
   water will turn green. This is commonly called an "algae bloom" and is
   usually caused by too much light like direct sunlight.
   An algae bloom can be removed by filtering with micron cartridges or
   diatom filters. UV sterilizers can prevent the bloom in the first
   place. Green water is very useful in the raising of daphnia and brine
  Film algae
   Grows on the aquarium glass and forms a thin haze. Easily removed by
   wiping the glass. Considered normal with the higher light levels
   needed for good plant growth.
  Spot algae
   Grows in thin, hard, circular, bright green spots, usually on the
   aquarium glass but also on plants under high light conditions.
   Considered normal for planted tanks. Must be mechanically removed. On
   acrylic aquariums, use a cloth pad or a gentle scouring pad like a
   cosmetic "Buff-Puff" and a lot of elbow grease. On glass tanks,
   scraping with a razor blade is most effective.
  Fuzz algae
   Grows mostly on plant leaves as separate, short (2-3mm) strands.
   Considered normal. It might be a less "virulent" form of "beard"
   algae. Easily controlled with algae eaters such as black mollies,
   Otocinclus, Peckoltia and siamese algae eaters.
  Beard algae
   Grows on plant leaves and is bright green. Individual strands have a
   very fine texture but it grows in thick patches and looks just like a
   green beard. It grows up to 4 cm. It cannot be removed mechanically.
   This does not indicate bad water quality but grows very fast and
   overtakes the tank, making it a "bad" alga. Can be eliminated with
   Simazine (Aquarium Pharmaceuticals "Algae-Destroyer").
  Hair algae
   Grows in bright green clumps in the gravel, around the base of plants
   like Echinodorus and around mechanical objects. It has a coarser
   texture than "beard algae". Beard algae will ripple in the water
   current, hair algae tends to form matted clumps. Individual strands
   can get to 5 cm or more. This is easy to remove mechanically by
   twirling a toothbrush in it. Can be troublesome if left unchecked.
   This is a popular food supplement for fish among European aquarists.
  Thread algae
   Grows in long, thin strands up to 30 cm or more. Tends toward a dull
   green color (hard to tell because it is so thin). Usually indicates an
   excess of iron (> 0.15 ppm). Easily removed with a toothbrush like
   hair algae.
  Staghorn algae
   Looks like individual strands of hair algae but tends to grow in
   single branching strands like a deer antler and is grey-green. Seems
   to grow mostly on tank equipment near the surface. Difficult to remove
   mechanically. Soak affected equipment in a 25% solution of household
   bleach and water to remove it.
  Brush algae
   This grows in feathery black tufts 2-3 mm long and tends to collect on
   slower growing leaves like Anubias, some Echinodorus and other wide
   leaf plants. Also tends to collect on mechanical equipment. This is
   actually a red alga in the genus Audouinella (other names:
   Acrochaetium, Rhodochorton, Chantransia).
   It cannot easily be removed mechanically. Remove and discard the
   affected leaves. Equipment can be soaked in a 25% bleach solution,
   then scrubbed to remove the dead algae. Siamese Algae Eaters
   (Crossocheilus siamensis) are known to eat this algae and can keep it
   in check. A more drastic measure is treatment with copper.
Prophylactics for Algae

   Algal spores are everywhere and will always be present in an aquarium
   unless drastic measures are taken. For fish only tanks, a properly set
   up ultraviolet sterilizer will kill algal spores in the water and
   prevent them from gaining a toehold.
   For planted tanks, this is not a good solution since the UV light will
   also oxidize trace elements needed by the plants and will limit the
   plant's growth potential. Unfortunately, conditions that are good for
   growing plants are also good for growing algae. Fortunately, plants
   will usually out-compete algae for the available nutrients. However,
   if there is an imbalance of nutrients, algae will opportunistically
   use whatever is not used by the higher order plants. Different algae
   will utilize different nutrients, causing sporadic outbreaks of new
   algae types in apparently stable tanks when a temporary imbalance
   An ounce of prevention is worth a pound of cure. To avoid introducing
   a new algae type to a planted tank with new plants, a simple bleach
   dip seems to work well. Mix 1 part bleach in 19 parts water and dip
   the new plant in it for 2 minutes. Immediately rinse the plant in
   running water, then immerse it water containing a chlorine remover to
   neutralize any remaining bleach. This will kill the algae and only
   temporarily slow down a healthy plant. Plants in poor condition may
   succumb to this treatment, but they probably would not have lasted
Algae Eaters

   The most effective control of algae in a planted aquaria is via algae
   eating fish. It is especially critical in the set up of a new tank to
   make sure algae does not get established before the plants have had a
   chance to establish themselves. For this reason and to help the
   biological filtration get established, it is recommended that some
   hardy algae eaters are added right away.
  Black mollies
   Black sailfin mollies are excellent candidates for the break-in period
   of a planted tank since they are cheap and easy to find. They are
   usually considered expendable and are removed after a month or so. It
   is important to NOT FEED THEM. If they are fed, they will not be quite
   so eager to consume algae. When they are hungry, they are eager
   consumers of most algae types seen during the break-in period.
  Otocinclus sp.
   Otocinclus are diligent algae eaters, but are best kept in schools due
   to their small size. One per 10 gallons is a useful rule of thumb.
   Various species of otos are seen in the shops at various times; most
   are good algae eaters but some seem to prefer the slime coat on fish
   to algae. Unfortunately, there seems to be no way to distinguish the
   "attack otos" from normal otos.
   Otos seem to be very delicate fish, but this is probably due to
   capture and shipping abuse rather than an inherent weakness. When a
   fish shop gets some in, it is wise to wait a while before purchasing
   to account for die offs. Most people report getting a dozen and having
   them die over a period of a few months until just a couple are left.
   Those then seem to last for a long time.
  ``Plecostomus'' sp.
   Plecostomus is the generic name for a wide range of sucker-mouth fish.
   Only the smaller types are useful in a planted tank, since the larger
   varieties tend to eat the plant right along with the algae. Two common
   types that are useful are the "bristle-nose plecostomus" and the
   "clown plecostomus" or Pekoltia. Both stay under 4" long and don't
   seem to cause too much plant damage. Sometimes broad-leafed plants
   like Amazon swords will be scraped a little too closely by the plecos,
   so they bear watching.
   Their diet can be supplemented by blanched zucchini and bottom feeder
   tablets. They also appreciate a chunk of driftwood in the aquarium to
   satisfy their need for cellulose. See the GOOD FIRST FISH FAQ for more
   information on keeping suckermouth catfish.
  Siamese Algae Eater
   Do not confuse this fish with the Chinese Algae Eater, which is very
   aggressive and does not eat algae. The siamese algae eater,
   Crossocheilus siamensis, is a very good algae consumer and is known to
   eat black brush (red) algae. The only problem is that these fish are
   hard to find in the United States (see the RESOURCES section of the
   PLANT FAQ for sources and identification paper). There are several
   fish in this family. The most commonly seen is Epalzeorhynchos
   kallopterus, commonly known as the Flying Fox. The Flying Fox is the
   more attractive of the two. It tends to have a brownish body with a
   very distinct, sharp-edged black stripe with a distinct, thin gold or
   bronze stripe above it. These tend to be very aggressive when they are
   full grown and don't eat red algae (as far as one aquarium reference
   is concerned).
   The other member is the Siamese Algae Eater. It is the same shape as
   the Flying Fox but tends toward a silverish body with a somewhat
   ragged black stripe. There may be an indistinct gold or bronze stripe
   above the black. These are definitely not aggressive; they are good
   companions for discus and small tetras.
   When they are young, the differences between E. kallopterus and C.
   siamensis may not be very apparent, especially if you haven't seen
   both types together. Unfortunately, most wholesalers don't sell fish
   to stores by their scientific name and the common names that are used
   sometimes get pretty silly (like "siamese flying fox"). If you really
   can't tell which one the store has, buy it anyway, but be prepared to
   sacrifice it if it turns out to be the wrong kind (unless your fish
   aren't bothered by it, of course).
   Farlowella are useful algae eaters although they are very sensitive to
   water conditions. They type known as the Royal Farlowella will get too
   large for a plant tank and may cause damage.
                                  FAQ: Snails
contributed by George Booth

   Snails are usually considered disasters in a plant tank, but with
   dense planting and good plant growing conditions, the right type of
   snail can be very useful by consuming dead plant material and
   detritus. Any damage they do cause will be compensated for by fast
   plant growth.

   The FAQs owe their existence to the contributors of the net, and as
   such it belongs to the readers of rec.aquaria and alt.aquaria.
   Articles with attributions are copyrighted by their original authors.
   Copies of the FAQs can be made freely, as long as it is distributed at
   no charge, and the disclaimers and the copyright notice are included.
Water Hardness

   Most snails do best in harder/alkaline water. If the hardness/ph drops
   below a certain point, their shells will start to dissolve and/or grow
   improperly (the behavior seems to be based on species). Malaysian
   trumpet snails seem the hardiest, showing little adverse effect from
   soft water. The Ramshorn snails shell will start to dissolve, and gaps
   will form in the new shell growth. Mystery snails will form gaps. Most
   of these problems can be corrected by hardening the water, and the
   snails will recover, although exterior shell damage (from dissolving)
   will remain.
Types of Snails

  Malaysian trumpet snail
   The Malaysian snail, Melanoides tubercularia, is an interesting
   creature in that it lives in the substrate during the day and only
   comes out at night. Its shell is a perfect cone shape and gets to
   about 2 cm long. It is a livebearing snail and reproduces quite
   readily. It is considered beneficial to a plant tank and doesn't seen
   to harm plants, even in large populations. They are hard to find for
   sale, but usually come for free on plant shipments. If desired, Clown
   loaches will keep them and other snails well under control.
  Ramshorn Snail
   Ramshorn snails are very common and come in various sizes. Their shape
   is as their name suggests. The smaller varieties (under 1 cm) are not
   too damaging to a plant tank, although they seem to relish the tender
   leaves of the Hygrophila family.
   The other type is the dark and light brown striped Columbian Ramshorn
   that can grow big as large as 2 inches in diameter. The stripes run
   the length of the shell with a pattern of random width light-dark-
   light stripes that stays constant throughout the snails life. These
   snails are extremely prolific and have a terrific appetite for plants.
  Pond Snails
   Pond snails are football shaped snails under 2 cm in length. They are
   to be avoided, as they will happily eat all your plants.
  Mystery (Apple) Snails
   One of the most beautiful kinds of snails are the Mystery snails.
   These snails have a shape similar to the Pond snail, but their spiral
   is rounder, and they grow much larger. They can reach tennis-ball size
   if well taken care of. The come in many varieties. The snail's body
   can be dark, or almost albino (very light with a bright orange speckle
   pattern). The shell can be dark, bright orange, albino, or
   multi-colored striped (length-wise like the Ramshorn). The Apple snail
   variety typically has the multi-colored stripes, with a dark body. In
   general these snails don't eat living plants. They prefer algae and
   dead plant/animal material (canned spinach will get you a very large
   Mystery snail).
Snail Prophylactics

   To guard against unwanted snails, use a weak potassium permanganate
   solution. The Manual of Fish Health recommends a concentration of 10
   mg/l as a 10-minute bath as a general disenfectant for aquarium
   plants. Then rinse them in running water. This kills snail eggs and
   parasites and might guard against algae spores.
   Alum is also useful. Get "Alum U.S.P." at the drug store. Soak the
   plants in a gallon of water that has up to 10 teaspoons of Alum. The
   Alum kills microscopic bugs. Longer soaks (2-3 days) will kill snail
   eggs and/or snails.
   End of Disease FAQ.

User Contributions:

Comment about this article, ask questions, or add new information about this topic:

[ Usenet FAQs | Web FAQs | Documents | RFC Index ]

Send corrections/additions to the FAQ Maintainer:

Last Update March 27 2014 @ 02:11 PM