Hello. I have been trying to cover the back wall of my biocube with gsp and have lucked out twice. I bought 2 different frags and glued them on the the back and for awhile they looked great then slowly they start turning white and then they just shrivel up into nothing. I thought it was the light being to bright but I have a huge piece of gsp on a frag rack that looks great. I don't want to cut it up and try again if I'm doing something wrong. Any ideas???