How about discussing how in the heck I'm going the fund my new tank while I'm out of work. Haha, I'm up for any topic. Except perhaps lighting; that has been beaten to death imo.
Um, how about reef safe fish or inverts you normally wouldn't think of, uncommon charges. Aposymbiotic corals or those with low reliance on bi-products of zooxanthellae (perhaps this crosses over to much into coral feeding discussion). Maybe proper DSB care or is that asking for trouble? Um, feeding fish with special needs, antias, dragonettes ect. Or perhaps culturing live foods, rotifers, brine anything... Just few ideas.
Let's talk about Calcium Reactors. How to set them up. How a person figures out what their specific needs are. I get alot of questions concerning Calcium and Alkalinity. How to test them, and what the numbers mean.