Don't turn off the filter!! The BB is going start to die in a few hours if you do that. Use AQ salt, 1 tsp. per gallon and VERY clean water. I hope gets better soon! Oh, and that's not the "Mystery Disease". It looks more different.
You could take out the filter, but not off it while it's in the tank. When you turn it back on, after a few hours, the bacteria has already died and is ammonia. That's basically using the filter as an ammonia machine! <--- Don't do that. I already know that Bettas can survive without a filter, thanks. My Betta doesn't have one.
Your fish has no sign of fin rot.
HOWEVER, if large chunks are suddenly disappearing, and your betta looks otherwise fine, then he's tailbiting.
Sometimes bettas tailbite due to stress, boredom, or too small of confinement.
How big are the betta's tanks?
My Om used to be in a 1 gallon tank until he started nibbling away at his tail. I panicked and thought I was a horrible betta owner because suddenly there was this horrible "tail rot"....
I moved him to a 3 gallon tank, added lots of new plants and deco, and added 3 ghost shrimp.
He stopped until I gave one shrimp away, and he ate another. Now the 3rd is extremely elusive and the lack of activity in the tank is making him nibble on his tail again. I noticed that only when the shrimp comes around to look for food, Omelette stops biting and chases the shrimp, obviously having lots of fun.
Get your fish in bigger tanks with maybe some tankmates.
that looks like my boys tail:/ he got sucked into the filter while i was sleepin... i put some pantyhose on the filter so that it still works but it cant hurt him
Actually, its not the filter. He's been moved to a glass fish bowl for the past few days so I can gauge his possible recovery through the suggested treatments. And his fins were still deteriorating. The back fin is so ragged, now, its like something was dissolving it.
I've taken the time to completely sterilize everything in his main tank, moved him back to into the tank from the bowl and I've added aquarium salt to his water. He seems more energetic right now, but I'm still going to check with the local aquarium store to see if they can diagnose his current condition and suggest anything else aside from the salts.
I'll post pictures if there is any recovery. Thanks for the advice. :)
Actually, its not the filter. He's been moved to a glass fish bowl for the past few days so I can gauge his possible recovery through the suggested treatments. And his fins were still deteriorating. The back fin is so ragged, now, its like something was dissolving it.
I've taken the time to completely sterilize everything in his main tank, moved him back to into the tank from the bowl and I've added aquarium salt to his water. He seems more energetic right now, but I'm still going to check with the local aquarium store to see if they can diagnose his current condition and suggest anything else aside from the salts.
I'll post pictures if there is any recovery. Thanks for the advice. :)
Oo im sorry to hear that... hope he feels better soon