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View Full Version : Questions about powerheads/turnover rates.



JWeb
11-16-2003, 4:48 PM
Hi gang... getting ready to buy equipment to set up my 29 gallon fish + LR + (eventually) reef aquarium. I have a question about powerheads and tank turnover rates.

I will be building a 10 gallon sump (from a fish tank) that will house my heater and protein skimmer. I also plan on adding a holder for some kind of floss filter (or foam) and charcoal, if either of these become needed during operation (for down and dirty filtration). Yet, I will heed OrionGirl's warnings in response to my first post that mechanical filtration is not desireable since it traps the nutrients in the water away from the bacteria/cleaning crew.

In any case, I am a bit confused about turnover rates and the use of powerheads. From all of the reading on done on this forum, it seems that a turnover rate in the neighborhood of 12-15x per hour is desireable. Thus, I will aim for 29 gal/tank * 15 tank/hr = ~400GPH.

The questions are:

Does this total of 400GPH need to be handled by the sump return pump (and, thus, the overflow box)? Or, is this 400GPH target the sum of the sump return pump AND powerheads used for creating circulation? This is important as I need to size my sump/overflow for the approprate flow rate.

I plan on getting a MAG-5 for my sump return pump since I am looking at ~3 feet of head and want to maintain ~400GPH flow. Is this wise? I have read the many suggestions to use the Maxi-Jet pumps on the board, however, I am concerned that the Maxi-Jet is ALSO an "aerator". I don't want to be putting lots of fine bubbles in my tank as I think that is unsightly. Yet, I don't think I understand how the Maxi-Jet performs it's "mixing" function... maybe someone can clarify.

Which pumps would you suggest to ensure adequate circulation in the tank? What size in GPH flow? Can I simply add one or two small powerheads with swirling devices? Or, will one powerhead aimed at the return from the sump from across the tank be adequate?

In the end, this all doesn't seem to add up. I may be overthinking this and hope someone can help clarify.

Thanks for helping us beginners...

Jeff Webster
Amherst, MA

gcvt
11-16-2003, 6:49 PM
Your turnover rate is determined by adding up the gph's of all pumps and powerheads...not just the sump pump. The Maxi-jet powerheads have a spot on the nozzle where you can attach aquarium tubing to bring in air; if you leave this tubing off, they won't introduce bubbles into your tank.

JWeb
11-16-2003, 7:14 PM
gcvt, thanks for the reply. That answers my questions!

gcvt
11-16-2003, 7:40 PM
My pleasure :)

The Mag Drives are reliable and nicely priced pumps. I have a Mag 12 and haven't had any problems at all. The Mag 5 looks like it will work well for your size system. If you run 3' head and "T" off the return to have two outlets in your tank, you'll be running at about 12.5x turnover and should have good circulation. If that's the case, you may not need any additional powerheads...but you could always add one or two powerheads later on if you feel it's necessary.