How long has the tank been up and running with fish in it?
Have you tested the water for levels fo ammonia, nitrites and nitrates and if so what were the exact results?
Could you describe in further detail the size, shape, texture and appearance of the black fungus?
When you added the various medicines was there carbon in the filter media during the treatment?
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Thank you for the detailed information.
Basically said--the problem is directly related to unfavorable water conditions as ammonia and nitrites should never be present in an established aquarium.
They are both harmful and often lethal to fish. The reason there are chronic health problems in the tank is because of ammonia and nitrites.
The black fungus you are seeing on the fish is not a fungus but something called ammonia burn which is a reaction to the presence of ammonia in the water.
Fungi (fungus) are always white to grey in color.
What needs to be done in order to fix the problem is to rid the tank of ammonia and nitrites. The way to do this is:
1) Keep testing the water every other day. If ammonia and/or nitrites are present in any amount do a 20% partial water change. Ammonia and nitrites need to test at ZERO, no exceptions.
2) Drastically reduce the amount of food being fed to the fish as overfeeding causes excess fish waste and uneaten decaying food which are both fuel for ammonia/nitrite growth.
3) While ammonia/nitrites are still present in the tank do not change or clean the filter media as this is one of the prime areas where the beneficial bacteria will grow.
4) Discontinue the use of products that rid the water of ammonia and nitrites such as Amquel Plus as theses products are only a temporary fix and do not address the root cause of the problem.
5) Do not add anymore fish to the tank as this will put additional stress on the already taxed biological balance of the tank.
6) If you haven't already done so add some aquarium salt to the water at a ratio of 1 tablespoon per every 5 gallons of water. The salt will help the fish in coping with the nitrite problem and also serves as a general tonic.
If you follow the above instructions, ammonia and nitrites should disappear within 14 days.
Once ammonia and nitrites test at -0- and nitrates begin to rise will the tank be considered stable and balanced.
I would not recommend moving the fish to the 55 gallon tank until the current tank's water is rid of ammonia and nitrites. Once the water tests out fine then would be the time to do the transfer using all the water from the 30 gallon tank in addition to transfering the filter media from the 30 gallon tank's filter to the 55 gallon tank.
If all new water is used in the new 55 gallon set-up you will have the same ammonia/nitrite problem all over again.
Once all is resolved, ammonia/nitrites eliminated, it would be advisable to do weekly 25% partial water changes in addition to not overfeeding. This should keep ammonia and nitrites from not forming again.
Best wishes and please let me know if you have any questions.
If you're already using aquarium salt that great.
Nitra-Zorb's product description says "A convenient pouch of natural and synthetic ion-exchange resins that selectively remove ammonia, nitrite, and nitrate from freshwater aquariums. Nitra-ZorbTM also helps during start up by reducing unhealthy ammonia surges while establishing the aquarium's".
It either is not doing it's job or there is just too much of an ammonia/nitrite overload in the water for it too handle as can be seen by the water test results.
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