lol. Currently!?! With livestock, 5. But 3 are temp holding tanks for fish and coral. Should consolidate down to 2, maybe even down to 1, depending on what I want to do with the btas n the Lightning Maroons.
Edit: technically 6 since I have 2 copperbands in TTM
I had three until last week. My main 120 gallon, a 10 gallon Nano and a 25 gallon frag tank. I took down the 10 gallon because it was actually harder to maintain than the 120 gallon. I find it easy to maintain two -- three was too much.
40g and 10g mixed reefs. Not hard to maintain at all, but the 10g has some algae, kind of tough to keep that tank perfect. Might just make it an all Xenia or all softy tank
There's a 90 g display tank at our house, then Matt has a frag tank (I forget the size @<3-2-reef) and 55 g display tank plumbed together, a live rock Rubbermaid pond (with sump) in the basement at his grandma's, and he helps care for the 60g display tank at his parents house.. the 14 gal freshwater planted tank in our kitchen finally came down last year..