Boeseman's Rainbow Problem - Not Eating

[Termato]

Hi everyone,

Over the last couple of weeks some of my Boeseman's Rainbow have not been eating. It started off with just one and he ended up dying after a week. One more just died yesterday and now a third one is not eating. I can't find any information on this and it's starting to worry me. I've already lost two and I haven't found any good information on this yet.

The fish in question hangs around the top of the aquarium and doesn't go after food. No discoloration and the fish appears healthy, except the lonely behavior and not eating. Any suggestions would be helpful as I'm not exactly sure what the problem is.

I've already treated to tank for external illnesses and I'm considering doing a treatment of API General Cure but I wanted to get some other opinions first. Any suggestions!?

Thanks!

 

[MDB_fish_newbie]

Hope it was not the ones u got from me?

 

[Termato]

The first two were, but this one that is sick now is one I've had. The other three I got from you are as healthy as can be. They were healthy when I got them from you. Could have been something dormant. It sure took it's time to show up w.e. it was.

I was able to take the first one out almost right after he passed but the second one sat for a bit and I think some of the fish ate some of the dead body. I was mad at myself for not noticing it until the lights came on.

All my parameters are right where they should be:

0ppm of Ammonia
0ppm of Nitrite
5ppm of Nitrate (It comes out of the tap at 5ppm so I can't do anything about that. All tanks run 5ppm of nitrate because of this).
7.4 pH

I just started a API General Cure treatment for parasites so hopefully I can save this little guy and the rest of them. Everything I've found through my research says parasites but I don't know anything specifically about what's wrong with them. I'd rather have a more specific treatment but I guess this is the best I can do for now until I know more.

I should mention that the first two started swimming right up against my air stone where the current is strong before they started swimming at the top. All other fish are fine and only one has been affected at a time. Very strange.