A year ago I put a background on my tank after putting a thin layer of vegetable oil over it. This helped it to stick to the tank, and the picture looked brighter. More like it looks before you view it through all that water, which tends to make it look dark if its just taped on. I still used tape on the edges though. This worked great, the only downside is just recently I removed it, and when I did the oil smelled a bit off. No big deal, I just cleaned the glass well, and put on a new background. I have since read of people using petroleum jelly, this is probably a better alternative to the vegetable oil.