You can use any paint that is water based. I used a quart of Glidden from that famous home improvement warehouse (you aren't allowed to mention other links and/or companies on this website). You want to buy a semigloss or a highgloss. Personally speaking, I along W/most reefers out there prefer a black background, it helps hide powerheads, plumbing, etc. You also want to buy SUPER SUPER SUPER SUPER FINE steelwoll or wet/dry sandpaper and "scuff" the back of your tank. This will give the paint something to "grab" to. You don't want to scratch it, just scuff it. If you don't, the paint will more than likely peel/flake off. I think I used 600 on mine; the higher the number, the finer the grit. (you more than likely know this, but I'm just including it if you don't) You will need a minium of three coats. Make sure you let it dry at least 1-2 hours between coats (depends on temperature and humidity). Again, a quart should get you by...unless you have a 500 gallon tank. Write me back and let me know how it goes.