questions regarding the removal of a painted background

I'd fill the rubbermaid tubs with 50/50 mix of fresh and tank water. bring up to temp, and add fish and hang the filter on it. Since the fish will be a bit freaked, I'd loosely lay the lid on the tub so they don't jump out.
A razor blade should remove the old paint. Then I'd clean it , mask off the areas that don't get paint, and spray away. Another tip is to lay a couple strips of duct tape across the back where the filter will rest. That way, if you move the filter, you don't take a chunk of the paint with it. Instead of plain black, you may consider fleckstone paint. It comes in many colors.
here's a few pics to give you an idea of what it looks like
grey


teal



that should give you some ideas of what it looks like. There are , like I said, many colors available...tans, browns, greys, black with specks of grey and white......worth checking out
Bob

 

Man that paint is awesome...I have plain black on my tank. I will also look into it whenever I get the nerve and money for a 125G.

 

oh, one more thing.....fleckstone is slightly translucent.....so I'd recommend overlaying it with a layer of flat black if there is any light behind the tank.

 

Also - make sure you clean your glass before you paint - any smear, streak, etc will be much more obvious once you paint because it keeps the paint from settling flat on the glass in those spots.