Apparently what I was thinking was rot, or extreme mysterious rot (Sarah and now my 4 female sorority) was actually a "bacterial columnaris" which unlike cotton mouth one, you don't get the "blisters" or cottony look. I think when I had raised the temperature a little more to reach 80 (now it's at 78) it made it go faster -.-
Now I feel bad. And guilty. Because I'm the cause of my sorority dying -.- Because I thought it was rot. It looked and acted (sorta) like rot. I've seen columnaris, so I ruled it out - there's no cottony substance on them at all and they act fine. Well they did act fine now I have them sulking in a bare 10 gallon with only a heater
Best yet I don't know when or where I can get copper sulfate or antibacterial food.