did you cover the tank with the front lid after you did the background?
Yes. Cracking is due to drying out. Bentonite (the primary ingredient in kitty litter) swells a TON when it's wet. So as it dries, it shrinks. I would put some plastic wrap over it till you get the top and do a light misting daily. You may still have to fill some cracks as the moisture shifts around, but it will definitely help.What do you mean? As of right now I don't have a lid I was waiting for this weekend to get it. Could it be lack of humidity?