I would say get as big as you can fit and afford. As far as door height on a custom, the tank builder would probably be better to advise on door size and such since they will have to build in ventilation. Make sure they drill for a misting system if you plan on using one.

Depending on the size tank, and size of water feature, the pump you have will probably be adequate, but, why not have a bulkhead installed in the bottom portion and use a sump? You can even grow aquatic plants in the sump to increase bio filtration and improve water quality. Kind of like a reef tank refugium. You can have a water return bulkhead fitted as well.

I could go on and on, but you really need to decide on the tank and layout first. I think I gave you enough to think about to start off with.


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