WTFs need a minimum of 20 gallon for one frog with 10 gallons for each additional frog. A minimum tank size for two adult White's tree frogs would be a 24"longx18'deepx24"high Exo-terra, anything else is way too small for anything other than juvenile WTFs.

I recently acquired a glass tank that is L24, W12, H16.5. I'm mostly interested in terrestrial frogs, so right now this glass tank doesn't fit my needs.
Actually that size would be perfect for terrestrial frogs, so... you just need to find the perfect frogs to go in it