What's wrong with my frog?

[mccabesm]

Thank you all for your replies! Sorry it's taken so long. I'm a college student and with school just starting, it's been really hectic.
American Green Tree Frog

The enclosure is 12"W x 12"D x 18"H
There is only one frog in the enclosure.
I got him from PetSmart, and he was kept in a small enclosure with another green tree frog, 2 anoles, and 2 other types of long tailed lizards. There were 6 of them total in the enclosure.
The typical humidity is between 65 and 75%, and the temperature is usually between 71 and 78. I have a thermometer/hygrometer in the enclosure to monitor these. I spray the enclosure with dechlorinated water once a day to maintain humidity.
I don't have any special lighting for the enclosure. I was told that since they're nocturnal, they don't need any special lighting. The only lighting in the room is from my window and from my lights.
I change the water once a day with dechlorinated water. I haven't cleaned the enclosure yet since the day I set it up, because I've only had him a week as of today. How often should I clean it? I have found a few places where there are frog droppings, and I've cleaned those out as I've found them.
As I've stated before, I use dechlorinated water for misting the enclosure and for the water soaking dish. The brand is All Things Living. It's a turtle water conditioner, but it also advertises being used for frogs and other animals too.
The substrate used is a coconut fiber substrate and moss.
When I first set up the enclosure, I cleaned everything with warm water. I was told to never use soap, as the residue could harm the frog's skin. I soaked the coconut fiber substrate and moss in water, as the package directions told.
I assume he ate over past night, because I haven't seen any of the crickets I put in his enclosure yesterday. I haven't found any poop recently. I haven't really gone digging looking for some, but there hasn't been any visible.
I feed the frog once a day, giving him 4-5 crickets each time. There is no food bowl, the feeders just roam free. All I've fed him so far is crickets.
The vitamin/calcium powder I use is Fluker's Calcium with Vitamin D3. He was fed this at PetSmart, according to the worker I talked to.
The frog is a juvenile, but I'm not sure exactly how old. I've owned him for 1 week. The frog was captive bred and was at PetSmart before I owned him.
I have never handled him. I've wanted him to get settled in his new enclosure before I did that. Also, I know you're not supposed to do it very often anyway, since they have such sensitive skin.
He's in a fairly low traffic area. The enclosure is in my bedroom. I'm gone for long periods of the day, either at class or at work. There's more traffic in the evenings, but it's only me and sometimes my roommate, so even then it's not very high traffic.
When I first got him, he was placed in a little pet carrier from PetSmart. It's kind of like tupperware with air holes, and there was a damp paper towel in with him to keep some moisture in it. When I got home, I set up his habitat. He was in the carrier for probably an hour and a half, then put into his enclosure. I'm not sure if this is considered quarantined or not. He's the only one in his enclosure, so I didn't have to keep him separate from another animal.
He is not on any medication.

Update: He is not in his usual spot in the moss that he's been lately. I can't find him anywhere in the enclosure (don't worry, there's no way he could have gotten out), so I can only assume that he's buried somewhere that I can't see.

Thanks again!