Thanks, thought it might be. The only 2 I've seen are in the fuge. I haven't ran lights on the fuge yet, mainly due to $'s. Really like this reef community. First system I've ever set up so, starting from scratch. Thanks again!
It is some type of sponge very hard to ID specifically. But if it makes you feel better i have a ton of these types all over my tank and never seen an ill effect.