I picked up two Bolivian Rams 1.5-2 weeks ago. The first one never ate and passed away today. The second one ate the first couple of days. I treated them with API General Cure as a preventative medicine on day 3, but after that the second one started going down hill as well. Symptoms: not eating, thin, dark in color (unsure if normal or not), and not a lot of movement. His fins aren't clamped and he does wander the tank a bit, but not a lot. He needs food but I don't know what to do. This is my first issue with disease. What should I treat him with and should I treat the whole tank? Please let me know as well if the med you're recommending destroys the cycle or not. Ammonia - 0 Nitrites - 0 Nitrates - 5-15 pH - 7.4 (I do water changes twice per week to keep it stable, otherwise it creeps up to 8.2. This has been working though). 37 gallon Temp - 25C (77F) Stocking: 7 platys (I'm moving some of my males over to a different tank), 6 Sterbai Corys, 1 Bolivian Ram I also picked up some Marineland All in One Remedy, but it said not for scaleless fish and when I went to the website seemed more for external parasites?