Hey everyone, I was wondering if you could help me out with some questions.

My girlfriend and I have been taking care of our first ever frog, a WTF, for about four months now. He's been looking pretty sick the past few days so we took him to the vet. She says that he might have an impaction and we're treating him for it and will have him rechecked in a week.

Now, my question is, what substrate could/should we use when he take him out of his hospital tank? We currently have coconut substrate from ZooMed, but we are having trouble seeing his waste on it, plus we're not sure if he could have eaten some of it and caused this problem in the first place. So we were hoping to find something light in color that we can see the waste against at the very least.

We found a "moss mat" from Exo Terra that looks promising but I wanted to see what the thoughts were from you all here.

Thanks very much