Whenever they are small smaller is better. If you aren’t able to fit 2 hides in a water bowl in a 30 gallon for a baby/juvenile ball Python then you are using hides that are too large.
Ball Pythons like small spaces to feel secure so the hide should fit them pretty snuggly, not a lot of wiggle room. When they are older and more comfortable you can move them to the 55 gallon if you want but for now it would be much to big. Even the 30 gallon might be to large if you don’t fill it up with plants and such to make them feel secure
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