Secondary Infection?

[ECMarine]

Hey this is my first time here and I consider myself to be a novice aquarium owner having a little problem. One of my Black Mollies is showing white patches all over him. It doesn't have that grainy look of Ich, but I just dealt with a bout of it about 3 weeks ago. I used RidIch at half dosage (lotsa tetras in tank) for about 7 days, along with raising my water temp to 80 F. Before the molly wasnt affected but now he is showing the white patchy spots on him, also his eyes look a little swollen as well. So far a nudged my heater up a little more (should be about 82 F by tomorrow) and added aquarium salt at 1 tbs per 5 gal (recommended dosage on the carton) All the other fish look fine except for the one Black Molly. Any advice you guys have for me about what I might be doing wrong/right would be greatly appreciated. My tank parameters are below.

40 Gal Hex tank

Whisper 20-40 filter set to max 200 GPH (thinking about adding another 20-40 filter, tank seems to be heavily stocked, but according to the fish/inch rule I'm good)

pH-7.0, Ammonia-.25 ppm, GH- 75 ppm, KH- 120 ppm, Nitrites - 0, Nitrates - 20 ppm

Inhabitants -
1 Angelfish
6 Cardinal Tetras
4 Zebra Danios
2 Red/Blue Columbians (had Ich now are fine)
2 Black Line Tetras
2 Lemon Tetras
1 Diamond Tetras
2 Bloodfin Tetras
2 Black Mollies
2 Serphae Tetras
1 Pleko
1 African Clawed Frog

 

[Toirtis]

Welcome to the board!

Sounds like a secondary bacterial infection....upping the temp should ilicit a bit of an immune response, but I would quarantine and treat in a hospital tank, if possible, so you do not need to nuke your main tank with antibiotic.