i have 2 reef tanks one is a 40 the other a 29. the 40 has mechanical (emperor 350) as well as a nice size skimmer pluss a small powerhead for extra flow crossways and i run it all 24/7 except for the rare times one of my animals unplugs it all!(yep im thankfull its rare lol) on the 29 i have the same emperor 350 hob pluss a smaller hob with no skimmer at all. theres not alot of rock just a single large peice and a bunch of small ones i have frags on most of them, all soft corals. both tanks are doing well, but i have more growth in the tank with the skimmer so far but that is some due to lack of a moonlight in the 29 i think. just my 2 $ents lol
Beaux