I've been attempting to treat my 10 gallon tank with a variety of medications for two months now, but nothing seems to be helping my fish. I have a black molly and four small Cory catfish in the tank. At first, I thought it was ich, and treated it with malachite green. But then, lesions started appearing, resembling columnaris. I treated the tank with 2 rounds of kanamycin and Triple Sulfa. Pale white splotches began appearing on my corries, but never developed any further. Now, the corries have holes behind their front fins (oddly excluding my albino. He seems immune to pretty much everything). More white dots then appeared in smaller numbers, but they were to small to be ich. I flashed my flashlight on my black molly and she shimmered gold in the light, suggesting freshwater velvet. Each fish (excluding the albino again) now has a hole somewhere near their gill plates, my molly being the worst. At this point, I am considering euthanasia as I have tried salt treatment, heat treatment, paraguard, ickremedy, kanamycin, Triple Sulfa, melafix, herbtana (out of desperation), and I even just left it alone for about a week to rebuild the biofilter. I'm stumped because most ignore the deseases described should have killed any of my fish within that week on no treatment, and yet, all of them are still alive. I've included pictures, but my phone camera can't capture how bad they really look. I also would have added more than four, but it wouldn't let me.
My water parameters are as follows:
Nitrates- maybe 10 (I'm using strips so it's hard to tell)
Ammonia- .25 (I'm going to do water changes)
I have no live plants in the tank. There is a bubbler, and an aqueon filter. Hope you can help!