[callistra]

Pictures?

I do believe you need to be using conditioner to the water unless you are using RO or spring water and you've tested it regardless to be sure. Stress Coat or Prime is good. I see how old they are but how long have you had them?

Can you treat in separate hospital tanks? If not then be aware that treating in that tank could break down the cycle, and it's better to separate at this point anyway. I would get a good antibiotic like Kanaplex or Maracyn Plus. If they can't be found Furan-2 or Maracyn and Maracyn 2 in combo. For the bloat/bulging eyes I'd also add 1/2-1 tsp per gallon epsom salt, predissolved before adding.

 

[callistra]

Measure out 10 tablespoons of aquarium water and add a full packet. Take one 1 tablespoon per gallon for treatment. I believe the first day it says double dose so you would take out 2 tablespoons the first day and 1 tablespoon each subsequent day. You need to mix this up fresh daily and not use it over and over again.

I would look into the Kanaplex and Maracyn Plus in case the Maracyns in combo don't work. The fuzziness could be columnaris (pics would help) or some type of fungus and while Maracyn 2 has shown some effectiveness against it some strands are resistant.