Hello I have a few questions that I would like answered about Ich in general. So basically the tank got infected with ich once and it killed a oscar and Green terror and The Texas and Dempsey survived and were doing fine ich was gone and everybody was good. I got another Green Terror ich comes back and everyone gets infected... EXCEPT the Texas. So I treated the tank with one med and it didnt work, so then I switched to another med and the visual symptoma are gone. Im still treating to make sure it is erradicated. My question is how is my Texas seemingly immune to ich? Is it possible it can't affect him? He is not even breathing hard or anything. My second question is Ovbiously they have seen high amounts of ich meds. Im using Tetra Ick Guard tablets. Will the meds throw off the PH and damage bacteria in the biological filter? My third and final is now ich is gone and There is a bit of cloud eye on both of them. is this left over from ich/ secondary infection? And if so do I need to treat with anything or will the fish antibodies get rid of it?