that is the same size exo terra i used for one of my breeding trios. i kept the 2 females in it year round and put the male in for just a few months. it should be fine, just make sure you have plenty of foliage and hiding places.

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4.1 snakes, 4.3.2 crested geckos, 0.1 gargoyle gecko, 0.0.2 red-eyed tree frogs, 2.0 devon rex cats, 1.0 betta, 0.1 sun conure, 1.0 lovebird