I didn't think ADFs and kuhli loaches can kill bettas...

Today I found my betta, Phil, dead in his aquarium. All of his fins were shredded to ribbons, some were missing!
The only things in with him were my zedra nerite, ADFs and my kuhli loachs, I didn't think any of them could/would do that.

My next suspect it the filter. Phil got stuck on the intake before, but always managed to wiggle free.

He was only dead less than max 10 hours, could the fins have been from the loaches or frogs eating him, and Not the cause of his death?

 

Often times, fish will start snacking after it's died. I would suspect the frogs or the filter more than the kuhlis. My guess is that the fish died, then in circulating around the tank the fins got torn.

 

I'm guessing you may have made the fatal mistake of buying and African Clawed Frog, which can grow larger and kill other fish. Then again, I haven't seen your frogs.

 

I've owned clawed frogs before, and these are ADFs.

 

Alright. Then I'm guessing it's most likely your filter.