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drnihili
04/05/2010, 10:25 AM
I've had a Biocube 29 running for about 3 years now doing "ok" but not great. We're upgrading to a 60 gallon corner aquarium that we got second hand and I have a few questions about flow and filtration.

The tank has been running off a ViaAqua 750 canister (315gph) for filtration and a Danner 3 (350gph) just for flow. I'm thinking about shifting to a refugium setup up and moving the canister over to my freshwater tank. That would put 350gph through a 10-15 gallon refugium and I would add at least 600 gph in powerheads to increase flow within the tank. Figure about 75 lbs of rock, BRS Reef Saver or better quality. My main concern is whether I have enough or too much flow through the sump/refugium. Should I leave the canister on for the extra filtering? I'd appreciate any feedback on this setup.

I'll be building the refugium from scratch. I assume it's best to devote as much possible space to the actual refugium and leave only enough non-refugium area to house the return pump and a small intake area. I'm planning on putting the skimmer, heater, and some LR in the refugium itself. Is this correct?

Finally, since I'll be replacing the current drain line in the tank with a skimmer, I'd like to take the opportunity to update the return line. Currently, water is returned via a 1" vertical pipe with three of those flexible nozzle things (I'm sure they must have a name, but I don't know it). I could just leave that, but I've considered running a pipe down the back corner then splitting it and running two pipes under the sand to have two returns just above sand level at opposite corners. Would this be better? Given sufficient flow from powerheads in the tank, does it really matter where I put the return from the fuge?

Thanks in advance.

thegrun
04/05/2010, 10:35 AM
I would go with around 600 GPH through the refugium. Additional flow in the DT with powerheads or bypass of the refugium section will be needed if you are keeping corals. Max out the space for the refugium, but be sure to leave enough room for your skimmer in the intake section and the return section MUST be large enough to handle all the overflow from the DT when the pumps are off (do not rely on a back flow preventer).

drnihili
04/05/2010, 11:02 AM
Would I need 600 through the refugium even if I increase my powerhead flow to, say, 1600gph? And yes the plan is for a reef tank. We'll have a few fish (maybe 3-5 small ones) but mainly corals. It'll start with what we've got in the 29g: Xenia, Palys, Zoas, Mushrooms, Green Star, Brain, and a couple we were told were "leather" when we didn't know better, but which I think are something else (they look like trees).

Since the sump/fuge/return are all connected, won't the overflow from the DT use all that space rather than just the return section?

thegrun
04/05/2010, 12:11 PM
Your refugium will work with a lower flow, but if you increase the flow, it will most likely perform better (I shy away from being definitive ), as the cheato (macro algae of choice) will have more nutrients pass over it. The usual set-up for a sump/refugium is with three independent chambers. 1st chamber has the inflow from the DT and contains the skimmer, heater and optional filter sock, it flows into the second section which is the refugium, that flows into the 3rd section which has the return pump or drains to the return pump if it is an external pump. The first two chambers maintain a constant water level with baffles. Many skimmers need a constant water level to maintain a even skimate level, refugiums are also best at a constant water level to prevent the algae and/or live rock from being exposed to the air. The third section will rise and fall dependent on the water level in the DT. As tank water evaporates, this section's water level will fall. This section is where the float switch for an automatic top off systems is mounted. There are other sump configurations, but this is the most common.

drnihili
04/05/2010, 12:37 PM
That's the configuration I had in mind. I understand that with the pump on, the first two chambers will be at a constant level while the third will vary. But when the pump switches off, water from the skimmer should overflow the sump baffles equalizing and raising the water in all three sections, not just the return section. Or am I missing something?

Sounds like the DT will be ok with 350gph to refugium, at least to start, but that raising the flow later on may give me more nitrate capacity.

bertoni
04/05/2010, 03:35 PM
I would put more like 100 gph or perhaps less through the refugium. 600 gph sounds like overkill for that size tank. I think the tank should be okay with 600-900 gph in additional flow, although more is fine for some stony corals, like Acropora.

drnihili
04/05/2010, 03:46 PM
What about placement of returns in the DT? I haven't been able to find much info on this. Does return placement matter much?

bertoni
04/05/2010, 03:57 PM
Not really. Just put it someplace that's acceptable esthetically, and high enough that it's not disturbing the sand (if the tank has any).