I think indoors humidity would be the major concern. I know the guy (Mr.3000) with the 3000 gallon tank in his basement ended up draining it because of this.

If the tank is inside you would have to deal with humidity (some type of vent system), lights, and moving/filtering water.
If it is in a cooled greenhouse you just worry about moving/filtering the water.

The more I think about it, the more I want a greenhouse. I guess I should not do this untill I buy a house. My landlord might not be to happy.