Effects of environmental factors on the toxicity of chloramine-T to fish

T. D. Bills

The toxicity of chloramine-T, a therapeutant used to treat bacterial gill disease in fish, was evaluated under a variety of physical and chemical conditions. Chloramine-T was more toxic in warm water than in cold water at exposures of 24 hour or less, but temperature had no significant effect on toxicity in 96-hour exposures. The chemical was slightly less toxic to rainbow trout in hard than in soft water, but water hardness had little influence on its toxicity to channel catfish. The pH was the most important factor affecting chloramine-T toxicity; the chemical about 6 times more toxic at pH 6.5 than at 9.5.