I've got a really young baby betta that I've had for around 2 weeks now. Three days ago I noticed his color change from a silver body and blue tinted fins, to more of a yellow body and pale fins. His appetite is nonexistent and he is very lethargic, typically with his head in the gravel and tail floating up. Unfortunately he is so small it is hard to see any other signs to pinpoint a specific illness. He is in a 2.5 gallon minibow aquarium. The tank is cycled, all water tests look good except the ph which is sitting around 8. The water was treated with prime conditioner and aquarium salt. The tank has a heater where I try to keep the temp between 74-80 degrees. I created an uncycled isolation tank with new water and have placed him in this morning. I'm not sure where to go from here. Has anyone had a similar issue or any advice that would help? I'm trying hard to not lose the little guy.