pacosamus illnesses

Question
My pacosamus has what I believe to be fungus the white cottony patches. I have treated the tank three times now and he still has it. After awhile my other fish start to get sick with those patches. Is there anything else it could have causing the patches?

Answer
It is likely a fungus as you have already noted. However, maybe you should get a different treatment as the treatment you have may not be as strong as others available. However, if the algae eater was the only one with the symptoms I would not necessarily say it has a fungus. If the pleco has flat spots, not fuzzy or cottony, I would suspect natural color as some plecos have light patches. But if they are cottony as you describe it is definately a fungus. Get a different treatment and make sure to follow the directions, including the dose and water change requirements. I hope this helps. Let me know if you need anything else.