Useful FISH HEALTH information for tropical fish hobbyists:
COMMON FISHY ILLNESSES
& AILMENTS
Probably one of
the most common questions I get asked is “What’s wrong
with my fish?” Well, that’s a little hard to diagnose
without actually seeing the fish itself, but there are some common
ailments you should be familiar with, and you should be able to identify
when something is really wrong.
First off, you
need to have a “Fishy First Aid Kit” handy.
FIRST AID KIT
Yes, you can have a first aid
kit for your fish. My advice is to set one up before something goes
wrong.
-
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
Now that you have
all those emergency items on hand, here are a few basics to watch
out for that are indications your fish may be in trouble.
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 possibly know what
sick looks like.
SYMPTOMS
THAT ARE NOT NORMAL:
-
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.
BAD
WATER QUALITY
Symptoms: Your
fish are gasping at the surface, or swimming lethargically, or even
changing color – from bright to dark or dull. There are no visible
lesions you can see, but they may be swimming with fins 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:
Ammonia
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 problem.
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 problem.
Nitrites
Change enough of
the water to bring nitrites down to below 2 ppm (as with ammonia,
if this is a lot of water, 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.
Nitrates
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 power head, 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 teaspoon. 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 tap water.
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 tap water.
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 tiny organism that starts
with one fish, falls off and attaches itself to the tank glass or
gravel, then grabs onto another fish and spreads to the entire tank.
To treat it, you
must treat the entire tank. Medicine must be added to the tank to
kill the parasites – but be careful – if it’s a
reef tank, invertebrates are very sensitive to reef medications, so
really the only alternative is to remove the fish to a quarantine
tank.
Some people think
that ich is probably dormant in most tanks, and is probably 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
commercial products are Kordon's Rid Ich and Aquarium Products' Quick
Cure. 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.
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 aggressive species that are biting your
other fish. Change about 25% of the tank water and add 1 tsp/gallon
salt to promote healing. Healing should begin within a couple of days.
If it worsens,
it could be fungal or bacterial.
Fungal finrot
looks like clumps of cotton on the fins and usually follows injury.
Treatment for 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 smaller fish,
try a commercial product such as Maroxy. For severe infestations,
try a bath in methylene blue (enough so you can barely see the fish)
until the fungus turns blue or for about 20 min. Don’t add methylene
blue directly to the tank; or you’ll kill your plants and ruin
the biological filter.
Bacterial finrot
is whitish, but not cottony and can be contagious. The fish then need
to be removed from the tank and medicated.
Treatment for
a bacterial infection: Remove the fish to a quarantine tank and treat
with Antibiotics. This is stressful for the fish, and doesn't always
work, so be sure of what you’re doing before you try this. If
the fish is still eating, try an antibiotic food.
If the fish is
not eating, a bath treatment is necessary. A combination of Kaynamycin
and Furanace usually works, especially for Columnaris. Remove to a
separate tank and aerate heavily.
INJURIES
Sometime fistfights
will break out in your tank among species, and the combatants may
sustain injuries that are severe enough to bleed. 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. Do Not Get These Chemicals
in 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.
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.
DROPSY
This is what makes
fish swell up like a balloon and their eyes bug out. Dropsy can be
caused by a variety of things – the most common are high nitrates
in the tank and bacterial infections. The swelling is caused by the
fish is absorbing water faster than it can eliminate it,
Your fish may recover
with no treatment whatsoever, or may die despite your best efforts
to save it.
If there are no
water quality problems, you may want to attempt antibiotic treatment
in a separate tank.
HEAD AND LATERAL LINE EROSION (HLLE OR HOLE-IN-HEAD DISEASE)
This disease can
affect discus, other cichlids, and many saltwater fish. The fish develops
holes in its head and sometimes along its lateral line. The causes
are unclear but as in any disease, stress and poor water quality likely
play a role.
It’s interesting
to note that fish in planted tanks rarely get HLLE, which supports
the nutrition idea, since fish can nibble on the plants and obtain
extra nutrition. Or it may have something to do with the interchange
of plants and oxygen. Scientists just aren’t sure.
Remedy: First,
make sure water quality is optimal and reduce stress. Carbon filtration
may facilitate this problem, since it can remove nutrients from the
water. So if you are using carbon filtration, switch to another form
for a while, and feed a vitamin-enriched food in the meantime, paying
particular attention to vitamin C supplementation.
For stubborn cases,
some experts suggest metronidazole (Flagyl) to eliminate Hexamita
(a mildly pathogenic protozoan) from the lesions.
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. This is a little like bloat in a dog, if you’re
familiar with that malady.
To help, feed the
fish pre-soaked or gel-based foods. Green foods are also helpful.
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.
VELVET
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.
