Thank You Helene,
The dividers are plexi-glass or lexan or anything similar would work. I spray painted one side of each green. They are held in place by silcon caulk, must use pure silicone (rubber) they are safe for tanks. I can drain any section and they hold up well.(slight bend). I sealed them comletely, sides and bottom in case of possile disease or to maintain different water parameters. Our 20 gallon tanks are 30 x 12 x 12 inches, so each section is approx 10 x12 x12. I get the tanks when local store has them on sale at $20.00 each!! or used!!
ps: answered your email…the address was missing an “s”.