Dying Fish And Unknown Cause?

Hello, sad day today. Two days ago I lost Britany one of my painted platys, prior to her death I noticed what looked like very small white stringy substance on her and possibly patches or dots, she was also very bloated and squared off but there have been no male platys in the tank for several months so I found that odd. I figured an external parisite so I gave her a salt bath and followed the instructions acclimating her and whatnot, then I treated the tank with apI super ich cure ( half dose because I heard my Cory cats were sensitive) She died shortly after. Today I did a 25% water change and condished my water with prime as I found no other reason to keep treating the tank if the infected fish was already dead ( I know ich lives in water but I was not sure it was ich and I didn’t want to continue treating my fish if the medication would do more harm than good.) Today I lost my female pearl gourami. She showed little signs of infection externally and looked pretty ok. She was a bit largic before hand and maybe little duller but other than that she swam fine just like britany. She started to seem a little off balanced and pushed by the filter I figured she was just stessed from the water change and left her be. She died shortly after. One of my fish (Becky) has had a white patch for many months, lately she had been getting worse displaying swollen gills, bloat, heavy breathing, and white patches on head.

Now my question is
1. What killed them?
2. How can I treat it?
3 What caused it?

As far as new fish I got 3 new Otos in about two weeks ago ( to go along with the 2 I already had) one died a day later the other two are still doing fine. About a week after I got the otos I picked up 5 ghost shrimp just to help clean up. They are all doing fine. I did not quarantine of otos as I don’t have a tank set up and from research I have done they normally don’t survive the process.

Water chemistry
Ammonia: 0
Nitrite: 0
Nitrates: 0
Gh: 15/16
Kh: 7
Temp: 76

WARNING DEAD FISH PICS

 

Looks like you are dealing with a bacterial infection. The best advice I can give is to quickly remove any fish showing similar symptoms. In particular white patches. Either treat the sick fish in a hospital tank or euthanize them. Even with meds, recovery is unlikely. Do a large 50% WC and temporarily lower the temp. to around 74-75 degrees. Hope things get better soon.

 

Thanks For the advice, what would be the best med to treat with? And for a hospital tank I am on a bit of a budget would a 5 gallon bucket with a sponge filter be ok for the time being?

 

Thanks For the advice, what would be the best med to treat with? And for a hospital tank I am on a bit of a budget would a 5 gallon bucket with a sponge filter be ok for the time being?

If you don't have a quarantine just treat the main tank. You should use a combo of Kanaplex and furan 2 at the same. Kanaplex can be hard on a fish's liver, but it's better than losing all your fish to infections.

 

I am ordering kanaplex now does anyone know it’s effects on snails and shrimp?