Indoor ponds are pretty common in Canada ... You shouldn't have too much problem with mold in the room provided that:
1. The room is of a good size & well ventilated (so it doesn't get too humid).
2. There is not too much of a temperature variation - pond to room & also daily variation of the temp in the room - so there will be minimal condensation. <Also the room need to be fairly well insulated if you are in Canada - otherwise water will condense on the cold wall & that will give you mold ... But I don't suppose freezing weather is a problem in Florida!>
Our kid's school has an indoor pond (goldfish). It is in the central atrium (no outside walls) about 2-3000 sq feet and a 16' ceiling. No problems with condensation at all. <Of course, we have very dry winter in Alberta, so humidity is never a problem.... might not be able to generalize to very humid locales...>
Finally, a shallow pond has much higher surface area for evaporation, compared to tanks (esp. tanks with canopies), so the 2 are not totally comparable.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.