Is this why black substrate isn't recommended for Flowerhorns?? I moved my 3-4" FH into a 75 gal in the livingroom and used black sand. The 1st picture is right before the move and the 2nd one is after! Is this the reason you guys always say to use light sand? lol Wow, what a difference, he turned black! It sort of looks cool but I know they're not supposed to look that way. Yup, that's me. Won't listen to anyone and just have to see for myself :-/