Any Suggestions, Sick Corys

two weeks ago I bought 10 panda cory cats. When I got home 3 of them were swimming upside down. I thought they might have been overfed, but also didn't want to risk infections so I separate them and put them in my quarantine tank. I first put them on a fast and after 3 days feed them boil peas(mushed up) and as well as an antibacterial treatment. They seemed to get better, but today I came home to one dead(the smallest of the three). Any suggestions on what else I can do to help em out? The other 2 seems pretty good they seem pretty energetic

 

What’s the tank size? Do you have a test kit? Did you use dechlorinater?

 

its a 10 gallon that I'm using as a quarantine tank and its cycled. I don't think the tanks the cause because I do daily testing on all my tanks.

 

Could you list the ammonia, nitrite, nitrate? Also, what’s the temperature? Cories are very sensitive fish.

 

(sorry late reply I ran out of my testing stuff and had to wait until after work to buy more) my ac broke and the tank is at 80F without the heater.(I know its not the best temp so I'm trying to cool it down while the ac gets fixed.) Ammonia-0 ppm. Nitrite- .50 and Nitrate- 0 ppm (around there). The water that comes from my sink is really hard for some reason.

 

What's the size of the main tank? Are you using API liquid test kit? Don't worry, I work at a LFS and our ac broke and our tanks were around 88.

 

main tanks 75 gallon and they aren't in it. Also yea I'm using the liquid ones. I hate the test strips they never work correctly for me

 

So, the 10 gallon isn't cycled, it has .50 nitrite and 0 nitrate. As I mentioned, Cories are very sensitive and can easily die from even .25 nitrite.

 

ah dang I could put them in my 50 gallon tank but I worry that they could pass on whatever they have to the other fish in the tank since it contains oto cats and shrimps. Though currently the other two do look at lot better and seem to be eating everything I gave em pretty fast. I was using new sand very thinly covering the bottom of the quarantine tank so that they can dig but so I could see if anything is there that's not supposed to be. I should probably take some from the other tanks and put it in there instead...