Clean Glass well ,then wipe it down with alcohol(rubbing works).Rustoleum woks just fine........I used flat black but was told that the shiney stuff works better.............I have had no problem in 6 mons,,not even a wet spot as alot of water has been splashed on it and it still looks great no streaks at all. You can touch it up if you need to so no worries.
Also I have gutted a house around a tank once ,just sealed it using window seal kit (for doing cheap windows for winter) ,the plastic one you put the two sided tape around the top part of the glass lay plastic over and shrink to suit. put a air line tubing outside to another room, had a air stone in tank for pos. fresh air pressure in.......worked great.Of course you must have the lights off...and I used a charcoal filter on the intake just in case......
Hope this helps a little.............Oh yeah I left a couple inches un painted just below DSB so I could see what was going on in the sand (like Cyno).
ScottbytheSea/