I am really new to this, but recently bought a tank from a friend (20 gallon), when she upgraded hers. She supplied it with the filter and the heater that she used. We purposely didn't clean the filter before transporting just to help when I set the tank back up. She gave me some of her sailfin mollies from her tank, 1 - 3 inches long and 4 babies just under an inch with 2 other babies smaller.
I added water conditioner, aquarium salt, stress coat and a live bateria to improve the filter. That was 3 weeks ago. The tank looked really bare so I spoke to my LFS and asked advice about getting some new fish, they said because I had used the original filter that the tank would be fine, that all the bacteria levels would be ok by now. They suggested 4 smallish sunset platys, 3 small red platys and 6 large neon tetras.
The fish all looked healthy in their tanks. I stupidly never quarantined any of the fish, (lesson learned). After 2 days I noticed what looked like Ich on my tetras, but not on any of my other fish so I began treating them for this. All that happened was 3 of my tetras lost their colour and died, then the other lost their colour too. I removed them from my tank and they proceeded to die, but thats not my problem now.
One of my red platys became very listless 3 days ago and is hiding among the plants in the corner of my tank. I noticed yesterday that she has a white patch at her tail just before her tail fin and her fins underneath have became white around the edges. Her fin on her back is down.
Today 1 of my male sunset platys is exactly the same, same listlessness, same with his fins.
I've read every fish condition website I can find and apart from being really confused about what it is, I have no idea what to do next, no sure if I trust the guy in shop is looking out for my or my fishes best interest. I have been doing partial water changes every second day about 15%. The temp of the tank is 78, when the light is on, and drops a degree or 2 when the light is off.
P.S. Can i just say that it hasn't stopped them getting jiggy if you know what I mean.