Thats actually a really good idea that ill keep in mind, but i actually dont like backgrounds on rimless tanks. I wanna be able to see straight through the tank. I used those sponge filters cause hopefully my scape and along with the plants(when the grow in) will hide the sponges. Where did you even buy that kind of foam? Oh, and i worry about crushing my shrimp as well. Shrimps are suppose to make us happy, but seems to stress me out more than anything... And make me broke!