What’s Wrong With My Male Platy

Hello, I’m wondering if anyone can help me figure out what is wrong with my male platy. I got a total of four platy and two balloon bellied mollies and I put them in my 25 gallon tank. Everything was going well until three platies began bullying the one smaller platy, who soon died. Then one female platy gave birth (she was pregnant when I got her) and soon died a few days later. I was very concerned since this obviously should not be happening, so I got my water tested and everything was normal. I continued my weekly water changes and my fish were doing very well. However, it’s been and a couple months since then and my last male platy is acting very oddly. He is staying at the bottom, not really eating, and breathing semi-heavily. So in response, I slightly lowered the temperature to about 75 and changed some more water (each time I change water I use quick start). Lastly, his stomach seems to be heavier on one side than the other- yes I know it’s weird but look in the pictures. This seems to kind of be like how the others died as well. All of my fish are doing very well, so I'm not entirely sure if it’s something wrong with my tank. Thank you for all of your help!

 

What are the water quality parameters?
Tankmates?
Btw when your fish is sick, typically you will want to raise the temperature, no lower it...

Sorry about your fish! Is the tank cycled? Do you see any abnormal bodily features? (ex. White stringy poop, fuzzy white scales, bloated) Again, I'm really sorry

 

Parameters: so my ammonia was .05 and they suggested that continual water changes would get rid of it so I’ve been doing them weekly. The Nitrate was 5 and they said the same about it as the ammonia, nitrite was .2, no chlorine and 7.1 ph. I have four mollies and two platies, but I do have 5 platy fry. For temperature, it was already on the higher side for platys and he was breathing heavily so I thought cooling the tank slightly would help, but maybe I should put it back up? My tank it cycled and I use apI quick start so it helps with that and he also seems a bit bloated but that is all I’ve noticed so far. I just think it is odd that my platys are the only ones with problems. Thank you!

 

Wait so your ammonia is 5ppm?

 

Wait so your ammonia is 5ppm?

It’s .05 ppm sorry

 

I see dropsey forming...raised scales