We've been using Aquarisol. There's something else called BettaZine I think that we're looking into.
Okay, here's the update: Bianco made it through the night okay. His fins are less clumped, but still not quite fully extended. I've cleared off my dresser to make room for a new 10 gal setup we're getting today. I hope to eventually, once he's healthy again and after a thorough cleaning of everything in the tank, to put an opaque devider in the tank so he gets five gallons to himself, and I have a seperate five for the guppies I want.
We're also getting a heater, a thermometer and a filter today. It's gonna be pricey, but I want to do anything I can for him. I was so relieved to see him alive when I got up today.
Unfortunately, the yellow stuff has gotten worse, and now it's gotten so he looks fuzzy around the edges. It's funny how the only fish disease I knew of before I got Bianco was ich, and I thought that was the ultimate nightmare.
I'm almost certain now that it's Velvet. Fortunately, we have a HUGE bottle of Aquarisol from my mom's medicine reserve under the 50 gal tank.
Wish us luck, and send Bianco some love. Ganesh willing, he'll pull through this.