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View Full Version : what size return pump do i need?


b190again
12/29/2008, 01:13 PM
Hi everyone, I'm setting up my new system and I'm not sure how powerful my return pump should be. I will be using a 35 gallon long tank as my sump to house the skimmer, refugium and heater and run it to a 15 gallon "high" tank above. what size pump would you salty old veterans suggest I implement to get adequate water flow.

thanks in advance :)

sean_954
12/29/2008, 01:16 PM
Shoot for 2 -5 times your DT .

reidcrandall
12/29/2008, 02:44 PM
How big is the display?

b190again
12/29/2008, 02:54 PM
the display will be 15 gallons, thanks Sean

reidcrandall
12/29/2008, 03:04 PM
Something like this: Mag 250 (http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MAG2&Category_Code=MAG) Would be good. You might even want to put a ball valve in to scale it back a bit. It would give you plenty of flexibility. I would only use it internally though. Mags are not good external pumps.

b190again
12/29/2008, 07:46 PM
I was thinking of a Mag2 or Mag3, thanks for the recommendation.

stricknine
12/29/2008, 11:55 PM
All depends on the size of the overflow. As mentioned above, make sure you throw in a ball valve to restrict flow if req'd.

Whys
12/30/2008, 02:31 AM
Your sump with fuge is twice the size of your DT? That's a little different and could throw-off the general rules-of-thumb a bit.

You're going to need to calculate the likely pump head pressure.
http://www.aquariumpros.com/articles/headpress.shtml
http://www.reefcentral.com/calc/hlc2.php

Then consider your overflow.
http://www.reefcentral.com/calc/drain.php

DT turn-over should be at least 10x with many hobbyists strongly recommending at least 15 to 20x. Some claim more is always better, but unusually high flow rates can add complication to the setup.

If you can, you'll want to give the fuge its own slower flow rate. I've seen it range from 3 to 7x, tho it ultimately depends on your intended purpose.

Personally, I don't know what calculating the flow rate in your sump is really worth. As long as dirty water is coming into contact with your mechanical filtration at a rate faster than it is getting cleaned, then what's the difference? I guess controlling bubbles could be an issue if the flow is way too fast, but given that your sump is TWICE THE SIZE of your DT, it shouldn't be an issue.

But I'm no veteran. ;)