Very true, Beverly. What i meant about them being a problem is that it is harder to clean floss or foam in a canister. I took the foam and floss out of my HOB's when I filled them with LR.

Any thoughts on my original question?

You could add a Koralia and a small media reactor. You could prbably get the whole thing for a hundy or so. 30 for the Koralia, 50 for the reactor and another 20 or so for a powerhead for the reactor.

Yeah, a canister seems harder to keep clean than a HOB. I have never used a canister, nor have I used Biomax - just foam so I don't really have an answer to your question. But I do like using foam. It traps detritus so it can easily be removed/exported from a system. LR will provide more surface area for bio-filtration but you can't really take it out and clean the crud out of it. Do you vigorously rinse your biomax frequently?

In my AC70 I cut the filter foam in half lenthwise, so I can use the other half at a later date, then put the carbon in and then instead of biomax I use LR. same idea I suppose, and this allows me to rinse the foam often, while still trapping detritus.

you could always use an AC as a fuge too the mod is pretty easy i think

I had a 33 gal running and never used a canister filter, just used a Aqua Clear filter and 2 power heads actually Koralia Nano's. My tank had only softies and LPS's though.

I ran my original first two tanks, 72 gal and 95 gal with canister filters and when I took them off at first I was worried.

Best thing I ever did. Having said that... what do you have in your tank for corals, fish and how much live rock?

I take it you're using the canister output as a flow supplement? I have a Rena XP canister running carbon on my system & while the nozzle does provide a bit of flow, the bulk of my water movement is provided by a couple of VorTech MP40s. I certainly don't consider the canister flow even close to adequate for providing water movement in my system. The canister simply provides a tiny bit of extra chaos near the middle of the tank where the VorTech flow drops off. And I consider it a little self contained mini sump, adding another gallon or so to total water volume. Every little bit helps when you're running sumpless.

Having said all that, is there a reason you can't do both as I do? Just add the Koralia or whatever powerhead suits you needs & continue running all the other filters. Trying to save power?

what are your other pump's for flow?

Can you increase those and keep the canister?

IMO i'd keep the fluval. HOB's are great, sure but the fluval devastates it definetly. I run my fluval 205 on my 75 with foam, chemipure, activated carbon and biomax. Couldnt be happier with it, everytime I clean the filter its scuds galore.

This is my tank...
http://www.youtube.com/watch?v=82rPEl0_mzo
33 gal long (48x12x12), 65 lbs LR, Fluval 404 (biomax), two Aquaclear 70 HOB's (LR rubble), Koralia Nano 425, Tunze 9002 skimmer, cheato in tank
Mostly LPS and soft corals, a few easy SPS

The reason it is an 'either or' situation is that I live in a very old building with old wiring and I can't really add any more to the circuit.