curious

I was wondering if the 8x4 sheets of green foam from lowes are safe to use for a 3d background? Any experience or knowledge with this? Thanks to anyone who can help me out.

:-? The same "worrysome" behavior you see when one of your little guys are about to bite the dust. Up and came out of no where too. This morning it was perfectly fine, and now this. NLS is the only thing fed. Regular water changes. All water tests are with in the same range they have been at...