Fish Diseases

Probably one of the most distressing times of your aquarium with you and your fish, will be when your fish are ill. I mean, there you are, proud of your new fish and aquarium and – bam!! Your fish are covered in spots, or wool-like, small tufts on the body. Your mind will be racing, and thinking things like: What the hell is that stuff? Is it incurable? Will it infect all the other fish? is this game over for all of my fish? Yes, its a worrying time, thats for certain. So to help you to catch an illness quickly, here are a few (only a few, there are hundreds of diseases around) of the more common tropical freshwater fish diseases

Examples of fish diseases


To see an example of a Healthy Fish.

Symptons of illness It could be… Treatment
Your new fish have died – there are no obvious signs of illness “New Tank Syndrome”
Adding fish to a brand new aquarium stresses the fish, and sometimes it can be fatal. For more info, check out: The Nitrogen Cycle
Loss of appetite An enviromental problem, newly-introduced fish can be slow to feed (stress), certain fishes will refuse anything but live foods. Enviromental: inspect for any manifestations of disease, and get a basic water tester (Ammonia etc). The same with stress. Be patient with them. Look for other signs of disease.
2,3) Cotton Wool effect on the body Fungus, Columnarius (Mouth fungus)
If you see this disease, can use medication (ie “Anti Fungus”) and a Salt bath (1 teaspoon per gallon)
1) Small, white spots on the head, body and fins. Whitespot (Ichthyophthirius)
A very common disease (especially in a new aquarium). There are several formulas around, dose the fish quickly before the parasite spreads. Salt could be used (1 teaspoon per galloon).
8) Fraying of the soft tissue (fin membrane) Fin Rot, the disintegration of the fins Use medication before a secondary infection occurs, it will take several days before there is serious fin damage. Could use salt bath (1 teaspoon per gallon)
Appearance of a whitish film over the eye of the fish Poor water quality, poisoning (Chlorine) or Eye Fluke Poor water: Water changes are required. Poisoning: Make sure to condition tap water. Eye Fluke: Use medication
4) Fish are gasping, on the bottom of the aquarium, red streaks around gills Most probably oxygen starvation, or a Gill disease You have too many fish, an air punp may help. Gill diseases are quite rare, you could actually see the gills rot away: use medication.
5) Worms are visibly seen hanging from the gills, fish are gasping Gill Worm (Dactylogyrus) This is another parasite. Use anti-parasite drugs as directed.
7) Reddining of the skin, or red streaks in the fins Virus, Ulcers (Bacterial infection) Viruses can only be seen through microscopes – and its incurable. With a bacterial disease, use a anti-bacteria or anti-internal treatment. A prolonged SALT bath (3-5 g/litre for several days) will alliviate osmoregulatory stress in the case of severe ulceration.
Scales seem to be raised, fish are bloated. Dropsy (Ascites) Dropsy is more of a sympton than an actually disease yet, and is quite common. Most associated with a bacterial infection (cause could be wide – poor water conditions are often the culprit. Meds can be used, but dont always work.
Small, worm like parasites attached to fish, fish scraping against rocks. Anchor worm (lernea) There are many Crustacean Parasites around, and can be exported into your water. Meds are available.
6) Dull colour (mucus), detached skin, fraying of the fin. Mucus Hyperproduction. This called by caused by Slime disease (parasite, meds available), poor water conditioners (high Nitrogenous wastes), fFukes, stress.

A word of warning with using medication: Obviously people want to save their fish, so they go and buy a product, and sometimes these can be quite effective. But a word of warning – some meds can be very detrimental in the long term. Treatments whitch use Malachite Green and Methylene Blue can be useful treatments for parasites and Fungus, unfortunately they can destroy our beneficial bacteria, and then you can get a Ammoni/Nitrite peak for some time. Also some meds demand it that they remove Carbon/Zeolite for the duration of the treatment – this can effectively start up a mini-cycle as the Carbon/Zeolite have lost their bacteria.

Salt bath: So a salt bath is a good way of treating the fish without damaging the bacteria we need. It is a good antiseptic and fungicide. If you are using high doses, its best to try to gradually raise the concentration, so the fish don’t become stressed. Sometimes it can be effective to use a short salt bath, with higher salt concentration (such as fungal infection – 10G/Litre for 30 min).

One Response to Fish Diseases

  1. Mitali says:

    If you use chemicals from the fish store it will add stuff to try to bring down the PH. The prbloem is all the stuff already in the water that makes it high in the first place is still in the water, so the two will fight with each other and the water will inevitably win. The result is fluctuating PH, which is much worse then a stable ph that is too high.There really is no cheap way to do it. You can try peat moss to naturally keep it down, but you would need to provide an extra filter that you can fill it with, and it will tint your water orange you would also want to make sure your water changes are more frequent and smaller in order to prevent jumps in PH at water changes.Using spring water, or investing in a reverse osmosis unit and mixing this water with your tap water, is about the only reliable method.It would be nice to know just what your PH is, most common fish have a pretty wide tolerence of PH. Your best bet is to just leave things alone and avoid delicate fish that can’t handle it. Keeping it simple usually leads to better long term success.

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