ahem... your looking for corals, asuming you can fit it into your basement do you already have your hay lights and/or itentics? Coral is going to be a small fortune and with lights, your looking at the price of a car. I strongly suggest, you buy your pond, and then get filtration completely planned out before you start thinking about corals. However to answer your question, armor of god is a good coral that reproduces quickly under right cond. Start with mushrooms, star polyps. Filtration is going to be a giant undertaking, mind as well buy another tank just to build a filter because HOB just wont cut it anymore. Please post pix, I would love to see this working out.
wow 900 gal... vtech just kicked in