Bacteria in the Aquarium and the Temperature Variable - Christina Pavon

Bacteria are unicellular organisms which multiply by simple cellular division; one individual divides in 2, 2 becomes 4, etc. The rate of multiplication is related to available food and environmental conditions. Raising the temperature, although frequently recommended for parasite problems, has an adverse effect on combating bacterial infections. 1ml of milk at room temperature can have a population of 9000 bacteria, if you increase the temperature to 95F, after 24 hours the bacteria population will grow to 50 million in that same 1ml of milk! When tropical fish are sick we raise temperature to increase their metabolism and promote antibody production. This increase in temperature also speeds-up the life-cycle of most parasites. If we do that on a bacterial disease it could be disasterous. At higher temperatures bacteria multiply faster than the fish's self-defenses can keep-up with. In this race, bacteria will always win.

Bacteria are present in every place of the planet. They cannot be killed easily with hot temperature, they can resist 15 minutes at 250F! It has to be this way because their job is to recycle natural matter. When they find an appropriate environment, such as an aquarium, they start to multiply and feed. In a poorly maintained aquarium, bacteria grows rapidly which can contribute to oxygen-depletion which leads to fish stress. Stressed fish have a lower pathogen resistance. The large bacteria population often finds a new source of food; fish's slime-coat. Discus in particular have a huge slime surface which could be attacked. In this way bacteria have an open road to internal organs and bloodstream.

We control bacterial overgrowth with frequent water changes. Sometimes no further medication is needed! If we were raising Goldfish, lowering the temperature to fight bacteria would be no problem. But tropical fish require a steady warm-temperature environment. The temperature can't be lowered when warm-water fish develop bacterial diseases because their defensive system could be lowered too. Discus in particular shouldn't be kept at less than 82-84F. If a bacterial disease problem exists in an aquarium and frequent water changes does not eliminate the problem, then antibiotics is the recommended treatment. But it couldn't do it if we stop water changes. The water changes must be continued during the treatment. The best way I found to fight against bacteria it's a total water change. Followed by antibiotic if it's necessary.