Help with Onyx!

[loveDelphine21]

My green veiltail Onyx is looking really sick. He keeps floating up at the top of his tank, and he will only move if I touch him. He won't eat either.

I'm treating him and my other betta with Maracide for their velvet. My other betta, Gypsy, is dong fine, but Onyx is looking really bad. What should I do?

Also, when I give a fish medicine, do I just keep putting the medicine in the tank and not clean the tank? The directions on the bottle of medicine are "Use 2 capfuls (10 mL) per 10 gallons of water. Treat on days 1, 3, and 5." And that was it. I have just been putting the medicine in the tank, everyother day, and I haven't cleaned either tank in a week. Is this right?

[loveDelphine21]

I also just shined a flashlight on Onyx, and he has a bloody red color at the base of all his fins. He has never had any red on him before. What is this?

[dramaqueen]

I would change the water after day 5.