Betta Fin Rot?

[nrsmac]

Hello!

I have a 10gal with 1 sunset Platy (i will get more soon), 3 pearl Danios, and 1 half-moon male Betta (Calisto). 3 months ago (when i got him) I had Calisto in a 1gal tank. He had the perfect half-moon shape with no tears in the rear fin. He now looks more like a crowntail. I have also noticed that the color of the fish has also changed. Is this because of a disease? I want him to look more like in image 1, but I don't know how do do it. I really like the blue/purple/pink/red coloration he has now as to the blue/green coloration to as before. He was in cold temperatures for a while in his 1gal (thats why I got the bigger tank with the heater.) Help me please! Any advice appreciated! Give me your email and I will send photos if you want them! Thanks!

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nrsmac

 

[phoenixgsd]

your tank is still not big enough for those fish, danios especially, can you tell us what your water stats are

 

[sumocopter]

I once had a betta who really didn't like being in with any other fish, he just wasn't himself and his fins began to go tatty even when in with just a few neons. Back in a tank on his own he came back to his former glory. Maybe Calisto is just stressed by his tankmates?