Checkerboard cichlid, Dicrossus filamentosa
These remedies along with their commercial counterparts are great for treating some illnesses and will have little or no effect on others. Protozoa infections such as white spot are easily cured but more serious internal injuries, tumours or organ failure obviously won't respond to a few drops of some potion or other. Be realistic with expectations about what can and what can't be treated. If a fish has a very obvious serious illness such as dropsy then euthanasia should be considered as the best way to prevent further suffering.
Can be used with fish which are sensitive to malachite green. It is a wide spectrum remedy.
Acriflavine will treat:
Some protozoa diseases like velvet.
Some external bacterial infections. Such as flexibacter (mouth fungus - which is actually a bacterial infection).
Using a 1% solution add 10mls/450litres
1% solution applied topically to wounds or fungal infections
Acriflavine is said to interfere with the spread of lymphocystis but this has not been proved.
Must be used with great care because copper is very toxic to fish. It is lethal to almost all inverts in both fresh and salt water.
Copper sulphate is not the recommended first choice treatment except for snail control due to its toxicity to fish.
Is a known carcinogen so avoid contact with skin when using it. Formalin has a variety of uses for treating fish but it is primarily used to treat external parasites. It can be used in combination with malachite green to make a wide spectrum remedy. Formalin will reduce the amount of free oxygen in water so it is important to aerate the water when it is being used.
Is another common compound which has a number of uses for fish keepers. It's primary use is to add oxygen to the water very quickly. If a fish is found alive after jumping from its tank, if a fish has been kept in a bag after purchase for to long or if there has been some equipment failure and the aquarium is found to be hypoxic (low in oxygen) then adding:
Hydrogen peroxide treats:
Hypoxia (low environmental oxygen levels).
will very rapidly boost the oxygen level in the water and buy enough time to sort things out properly. Do not under any circumstances add more than the recommended dosage in the mistaken belief that you are giving a little extra help because you may end up making things much worse.
How it works
Hydrogen peroxide (H2O2) rapidly breaks down in water to make 2(H2O)+O2 (water plus oxygen). As you can see there is no harmful residue left over from this treatment so there is no need for water changes.
Is one of the best treatments for fungus on fish. It can also be used to treat some external parasites.
Some fish such as scaleless species are susceptible to it and it may cause more problems than it solves, so don't use malachite green on fish known to be sensitive to medications.
Malachite green is banned for use on humans due to its toxicity, fish which have been treated with it should not enter the food chain and protective gloves should be worn when using it.
Malachite green treats:
Magnesium sulphate's main use is to treat digestive problems in fish. Use a separate container to treat the fish rather than add Epsom salt to the tank.
Magnesium sulphate treats:
Epsom salts are also used to harden soft water in order to keep Rift valley cichlids. But this should be avoided due to it's laxative effect on fishes. Fancy goldfish often suffer from trapped air which makes them buoyant. This is often mistaken for a swim bladder problem when in fact it is a digestive problem which in most cases is easily cured with Epsom salts.
This is one of more traditional older treatments which is generally poorly understood. It isn't just an harmless dye it is actually quite a strong disinfectant.
Methylene blue treats:
Treatment should be carried out in a separate tank because methylene blue will interfere with the filter bacteria possibly causing a rise in both ammonia and nitrite in well established aquariums.
Dosage: methylene blue should used at 2mg/litre in a long term bath for around 48 hrs.
Oil of cloves has a couple of uses, it is used to sedate large fish so that ulcers, wounds, loose scales ect can be safely dealt with without the fish risking further injury by flapping around. Great care must be taken when using oil of cloves because it is a true anaesthetic and the longer the fish is exposed to it the deeper the fish will be anaesthetised even to the point of cardiac arrest quickly followed by death.
It can also be used to euthanize fish which are terminally ill and suffering needlessly. Because it is a true anaesthetic the fish will become almost immediately numb on contact with oil of cloves and it's level of awareness very quickly falls. This makes it ideal as a sedative and perhaps the most humane method of euthanasia.
Even if a sedation dose is administered death will still occur if the fish is left exposed to the mixture for long enough. But with the increased euthanasia dose death will occur far more rapidly and without causing any undue distress to the fish.
Isn't widely used anymore due to its toxicity but it is a very good treatment for heavy infestations of external parasites especially on pond fish. It is also used to sterilize equipment such as nets ect.
Potassium permanganate treats:
Never use potassium permanganate with formalin. Overdoses will prove lethal to fish. Potassium permanganate will lower the oxygen level of the water, after treatment hydrogen peroxide will quickly restore the oxygen level back to normal, it can also be used when an accidental overdose of pp has been administered.
Has both anti-bacterial and anti-fungal properties. It is mainly used to treat wounds and fungus.
Povidone iodine treats:
Dosage: Apply topically with a soft brush.
Salt is a great remedy for all kinds of fish health problems, it is a bactericide, fungicide and it will also kill some protozoa and other parasites. In an emergency use whatever salt you have to hand other than marine salt because marine salt contains buffers which may affect the pH quite drastically by raising it to around pH8.4. It is often repeated that table salt must not be used due to the anti caking additives which it is said may harm fish. I believe that this is simply being repeated quite blindly by people who have no experience of it. I and many others have used it in an emergency without any ill effect what so ever, indeed I have never heard of any fish coming to harm which could be attributed to using table salt instead of some other type of salt.
*If salt is safe to use then table salt is safe to use.
Tips on using salt
Where possible always use a separate container to treat the fish rather than add salt to an aquarium because some fish are quite intolerant of salt and its addition to their water will place the fish under stress.
Where solutions above 0.3% are to be used it is a good idea to begin with a weaker solution and increase the salt level daily over a few days rather than risk shocking the fish.
Don't use salt in planted tanks, few plants will thrive with salt in the water.
Before using salt as a remedy make sure the fish being treated is salt tolerant.
Don't add salt to fresh water aquariums thinking it will act as a preventative measure against illness, fresh water fish live best in fresh water - i.e. no added salt.
See Treatment finder for commercial treatment
Commercial treatments use the same few compounds in differing proportions for many of the remedies sold in fish stores. These compounds are available to buy on their own usually from koi dealers because pond keepers tend to use this type of remedy in preference to store bought remedies which often don't list their ingredients. None of the treatments mentioned here are classed as controlled medications and are freely available to buy over the counter at the time of writing (2012).