only fish with serious ick are currently being medicated. The rest have just clean water and some have a bit of aquarium salt. I would love to keep them all together, but it would really be stressful because most all of them are sick and they would transfer disease to the others who are already sick, which I am not willing to risk. Each fish came with his or her own cup, and they are each labled so that is not an issue. As for the temp, I have them under reptile heating lights and their tanks are staying at a constant 79 degrees. (I am measuring the one on the far right, far left, and in the middle). Daily 100% water changes are needed wheather in a large tub or small, soI would prefer smaller. I am sorry If I sound rude. I am not trying to be at all, but this is what works for me, and many of the fish already look tons better! Now I am working on finding hideouts for all of them because most have noting in their tank, or maybe just a small plant. I am thinking I'll go grab some java moss because its really cheap in bulk at my LFS