rot infection or biting

I was doing a water change yesterday on my cichlid tank (75g, with 5 African cichlids, not 100% sure of specific fish names) and I noticed this little guy. I quickly got him out and placed him in a hospital tank. Before I did my water change the parameters in the 75g were: Temp: 80 F (26.6 C)...

   We are urgently seeking help for my Betta (male) who is showing unusual deterioration on tail. Purchase back in April he was my very first fish, and I tried/have done everything to T with him. He is in a cycled, 6 G Fluval Edge tank (alone), gets water changes performed each and every wk...