Wow, Scott, what a rough start Sorry you lost your frog! My four young White's tree frogs also came from Petco (two on Oct 1 and two on Oct 9, all from the same tank) and I can say pretty conclusively that I will never purchase another animal from that store. Within 3-4 days of purchasing our frogs one started having loose stool, eventually they all had it. I had a fecal test done and they tested positive for coccidiosis, an intestinal protozoal infection. Yesterday one of the frogs got a prolapse, so now I have to worry about that in case it recurs :/

#1. Answering the questions posted by Strider18 will help folks help you.

#2. In my opinion I would stop and undo EVERYTHING. Whites Tree Frog's need the proper temps and humidity, and keeping them in plastic boxes with or without holes is going to cause you way more problems. I'll let someone else chime in about your permanent setup, glue and etc. since I'm not to that point yet.

Here's my QT set up: I keep each of my Whites Tree Frog pairs in a 5.5 gal glass tank with a metal screen top lid. The tanks for quarantine should be MINIMALIST for ease of cleaning and possibly treating frogs (suggest highly you get fecal tests done). With reg room temp and a blue 60 watt light during the day and a red 60 watt light at night, I have maintained them at daytime temps of 77-80F and nighttime of 73-75F. Humidity is maintained at 50+% on average, going up to 70's% when misted, but not kept that high for any length of time. I use glazed saucers for 4" clay pots as soaking dishes and provide a couple of polished stones to help the frogs get in and out. I was using a live dracaena plant but now use silk artificial plants as they are easier to clean and sanitize (plastic is even easier but I don't care for the sharp edges). Substrate of choice: Damp Viva paper towels. Water: Bottled natural spring water in BPA free bottles (add dechlorinator). Food: Crickets daily, gut loaded on Flukers dry high calcium cricket diet; dusted once or twice a week with Reptocal with calcium, Vit D3, etc. Lighting: I use 6500k T8 grow lights/aquarium lighting (12 hrs on, 12 off) with the 60 watt blue & red lights for daytime/nighttime heating. Cleaning: Normally water change every day and spot cleaning for poo but when medicating should do a deep clean/disinfect daily of everything.

Anyhow, that's where I'm at for the moment. I hope your frogs will be fine and that you get a QT set up that works well for them. Good luck!

Here's the link to the White's Tree Frogs care sheet Frog Forum - White's Tree Frog Care - Litoria caerulea