I currently own 3 wtf and all the research I've done says moss is a big issue with the way the frogs feed. It causes impactions and digestive problems. I switched to reptile carpet and have had good luck but I have to work to keep my humidity up. Usually not an issue with a few sprays of water a few times a day. Keep an eye on the brusing and monitor poop to make sure the frog is passing there food ok. Carpet and paper towels make a very easy to keep track of bowel movements. Easy spot cleanup aswell! Hope this helps. Happy frogging ��