I use an AC70 in my 20gal & it has done a wonderful job, amazingly crystal clear waters & that's w/o carbon. Using 2 AC70's on my newly acquired 55gal SW, has great water flow/column. Using 2 AC110's on my discus 72gal BF (with one DIY extended intake tube into a tee to the bare bottom) - discus don't mind the increased water flow & filtering has been great.
but when I had a fluval on my discus tank, it was more of a hassle to maintain than the AC's + the problem of crud sticking in the in/out ridged tubing then back washing when started to prime, then also sprung a leak, that turned me off of canisters. no doubt they perform well but vs. the maintenance, performance, ease of care, cost effectiveness of AC's/hob's I druther not a canister anymore. seeing this thread continue to labor on about the o-rings the seals/gaskets, my my, how troublesome.
but do let me ask, any pics of your planted HOB? curious. can you use any plant or must be pothos? also what do you use for lighting? also, any debris it picks up gets flushed back into the tank or do you use filter floss/sponge?
thks, sounds like a great idea I may want to implement.
also, wonder what plant can be used for SW HOB?