paint thinner would work, but i prefer using a razor blade tool. Strips it right off and havent scratched a single tank yet. Actually I lied. I shaved a piece of trim off on the top of my 15 gallon .
Just used the regular krylon fusion spray paint in cobalt blue, and black. Favorite two colors
Jordan, I would actually use Paint Thinner because when I tear this tank down sometimes next spring to replace it with the wall unit I already have to buff a bunch of scratches out of the glass. I would rather not risk having to buff out more.
I used Speed E-Namel which was recommended by the Paint Store. Cost me $1.91 a can.