Why do 3 of my fish have swim bladder disease?

so my dwarf gourami had swim bladder issues and sadly died awhile ago (tried to feed him a pea but he wouldnt eat it) and now my molly is showing the same signs, and possibly also my dalmation molly. the water tests are normal and the tank is clean. i feed them tetra flakes and is that causing it?
update- when i try to catch him to quarantine him, he swims away and acts totally normal for awhile, then goes back to floating vertically in the corner

 

Be a good idea not to feed for a few days to allow a possible intestinal blockage to pass.
A 50% water change wouldn't hurt either.
Hopefully your fish aren't suffering from an intestinal bacteria infection. There's really no viable cure for that.
Hope things get better soon.

 

i put a pea in the tank and they all swarmed to it, so maybe thatll make the blockage pass. the sick ones been seperated. if its bacterial, do you just....wait for them to pass away from it or what can i do?

 

I never recommend aquarium specific antibiotics. They rarely cure & often do more harm than good.
If in your opinion the fish is suffering & has no chance for recovery, euthanization might be warranted.

 

hes been quarantined for about an hour (in a bottle with water from the aquarium) and is acting normal now?

 

Maybe things aren't quite as bad as they seem.

 

update: maybe it wasn't swim bladder? i discovered a fish bullying this one and another and he's been removed. they're pretty much better now