Hi there Sahara, Sounds like a couple of very well looked after frogs that are lucky to have such a caring keeper. I would suggest carpet Moss as it is nice and soft. Im not really sure how yours guys get around but if they can climb make sure the surfaces they are climbing are smooth. I would also make it very easy for them to have access in and out of the water. Im not too familiar with this species of frog. How are they getting around their enclosure and im assuming you hand feed them?