55 Gallon Tank Platy laying on side at surface, swimming in circles?

What new craziness is that? I turned on my tank light this morning and everyone seems fine except this one platy. She's laying on her side, kinda floating at the surface, and swimming in a circle. Now what?

 

I tried feeding the insides of a mashed up pea. Enthusiasm was minimal. Every time any one of my fish snatches a piece, they spit it out immediately.

 

Does it seem like she can swim down, or is she "stuck" floating at the top? Could be a swim bladder issue, or possibly an inner ear(how fish balance) problem.

 

She seems to be mostly stuck at the top.she swam down a little earlier but floated back up. That's why I tried the pea, it's what I keep seeing recommended for swim bladder problems. Do I have to worry about this being contagious?

 

Swim bladder problems can be bacterial, likely however, it is not and is due to a number of physiological problems constipated, bloated, dramatic changes in water chemistry, as well as being genetically predisposed, bad diet ect. Maybe try feeding smaller chunks of pea to her. If that doesn't help you could try increasing the temperature to about 80 and adding some salt.

 

I have salt in the tank, precaution as it's currently and will in the future be all live bearers. I feed TetraMin tropical flakes.
There haven't been any major changes in water chemistry, the tank is cycling but ammonia is holding at .25 and has been since I added the fish on Friday. No nitrites or nitrates yet. Temp is 78.

 

Perhaps a water change might help recovery as well.

 

I'm reluctant to mess with it atm. I'm cycling it with TSS and you're supposed to try to avoid doing a WC for the first 2 weeka.

 

Does the fish gills look red at all? Is it breathing rapidly or abnormally?

 

The fish is deceased. I gave the tank a dose of melafix as a precaution

 

I'm sorry to hear that, that's never fun. Swim bladder issues usually are not fatal, it seems like it may have been ammonia poisoning.

 

That's the odd part. The tank is cycling, so there's some ammonia, but it's at 0.25ppm. When I cycled my 20, it rocketed up to 4-8 and stayed there for over a week, and none of my guppies had this issue. I lost some, ironically, after tank parameters dropped to 0-0-5, then had an outbreak of what seemed to be columnaris, then when I'd finished treating that, fin rot and torn fins cropped up. I ended up tearing down and disinfecting the whole tank. But it definitely seems like ammonia is at a less problematic level here. I didn't know so much about cycling then, hadn't heard of TSS, thought stocking a tank slowly meant buying 3 guppies a week..... I know more now, so hopefully the 20 will behave now.