I used Lonewolf's painting method as practice on my quarantine tank. I had the benefit of learning from his mistakes. If you decide to do this, use wide tape and tape the ENTIRE tank except the side your painting. Be sure to overlap the tape and tape the top off too. That stone paint goes EVERYWHERE so paint outside and it drys very slow even in the extreme heat of Texas so be patient. I definately intend to do a display tank like this. Probably for primarily livebearers, the black paint looks best with red and yellow fish and green plants which are exactly what I like best personally. (There are 4 colors of that paint, a black, a red, a grey, and a off-white) Wal-mart sells another brand of stone paint and their colors look slightly different so check them out, they have a little lighter black color and I think they have a blue also.
My mistakes: instead of taping everywhere I tried to tape posterboard on the sides I wasn't painting. It didn't work, the posterboard pulled the tape loose and paint went where I didn't want it. Just tape the entire tank, on a 10 gallon its not that hard.
I wasn't patient enough and put a HOB on the tank before it was fully dry and the paint pulled right back off in some spots.
Lay the paint on thick, that paint may look like it covers but when your looking from the inside you will see where you didn't get it thick enough. Use the whole can for a 10 gallon tank. You will need more than one can for larger tanks.