If you added some ventilation to the top, perhaps if you put ventilation in the back, still I don't think this is a good tank for darts, I feel as though if you added some ventilation mossy frogs would be fine in it. Do ye research. Also can you even drill acrylic? I've never tried. Also yeah top only opening tanks make me want to cry too.I recently got a Marine-Land 30G Half Moon (27l x 27h x 18d) and have been trying to decide how I want to design it and that requires knowing what frogs I'm going to be putting in there. I've mainly been looking at tree frogs so far but want to consider dart frogs. I am looking for any suggestions on the species I should consider whether its tree frogs or dart frogs and also looking for ideas regarding the design of the tank. If anyone has, or can link me too, a vivarium in a similar sized and shaped enclosure for inspiration that would be greatly appreciated. I've been trying to find images of half moon vivariums and haven't had much luck.