Platy floats tail first to top?

I got the nitrites back to 0 the next day after another water change and amquel. I usually stick to a 20 percent water change bi-weekly and change the carbon filter monthly which has been working well. I felt guilty I hadn't noticed the filter backup (a bit too much algae on the intake tube) but work got crazy-busy and I was putting in alot of hours at work :( I also know that the tank is a bit overloaded due to too much fish-orgies going on! I gave away 4 of my babies to a neighbor who has an established 70 gallon tank and only a few fish. I told them I have more for them if they want! They said they want to allow the tank to adjust slowly to the addition first which I think is a good idea too. She is still kind of floating to the top - I am going to add some marine salt to the water as I have not done that recently. Has anyone heard of permafix for swim bladder? Is it harmful at all or should I try it? Also I read something about peas - I have some frozen peas, would these work? How would I feed those? Like, thaw them out and then throw them in, or what? Or what kind of peas do I get, fresh ones?
 
Novaqua is a water conditioner - it gives the fishies a coating of slime. And as I like to say, "a slimey fish is a happy fish"...
 
Pimafix is for fungal infections so unless she has an external fungal infection I don't see any reason to add Pimafix. As for the peas, they recommend those if a fish is constipated which can cause swim bladder. You can use either fresh or frozen (thawed) peas and you remove them from the outer shell as the fish cant get through that. You need to remove the uneaten amount though so it doesn't affect the water quality as well. You can try that as I would say it sounds like swim bladder and she is old (1.5 yrs is old for a platy). I would try the peas to see if it is a blockage that is causing her to have the swim bladder. I would also try feeding an antibacterial fish food in case she has a bacterial infection internally from this.
 
AquariaCentral.com