Sump pump rule?

SLPReefer · 10-30-2006, 01:47 PM

Is there a rule of thumb for how many gph per tank size you want for a return pump in your sump. I have 75g tank with 2 x ~1.5" overflow pipes and a ~15-20g sump. I am looking at getting a mag 7. Will I be happy with this pump? I am elevating the water 2' at the most. The sump is next to the aquarium, not under it.

Thanks,
Jeff

mtfatwork · 10-30-2006, 01:49 PM

Jeff I would think it would be fine. I would suggest putting a ball valve on both drain lines and one on the return line off of the mag 7, so if you have issues with the flow matching, you can adjust accordingly. Just a thought

rihanssu · 10-30-2006, 01:58 PM

wait, look and see what the drain GPH is on 1.5'' pipe, the reason i say is i think that the two of them is WAY more then 700gph, i have a single 1'' drain that did 600pgh you may be under powered. you might wanna talk to dirk and see if he has any dart pumps left. they are really nice and yuo cn always just ball valve them back if they are too much flow.

goetzc · 10-30-2006, 02:15 PM

I have a 62(tall 55) with a ~20 gallon sump. I use a mag 12 to a SCWD and part of the flow is T'd off for the refugium.

I love the alternating flow of the SCWD and my return is very quiet(dare I say silent).

Chris

mtfatwork · 10-30-2006, 02:57 PM

I use a mag 12 on my 220 currently as well. Just havent had time to finnish the final plumbing with the external pumps and all the jazzy stuff in the fishy room

ZoaCrazy · 10-30-2006, 03:09 PM

IMO, you should really try to match the gph that goes through your skimmer. Your flow shouldn't really be coming from your return ideally. JMO.

David Grigor · 10-30-2006, 03:19 PM

Providing your in tank circulation is coming from other sources ( recommended ) and not from the return pump then really just about anything around 500gph +/- some should be fine.

My personal rule of thumb is to keep your the skimmer fed and if your heater is down there just enough circulation to maintain heat in the tank. Anything more than that is a waste of electricity.

A OR2500 has more than adequately met that for all my tanks ranging from 58g up to 125g with no problems or concerns. For my instance, wattage is equally important becuase I use on an UPS so I'd rather have longer run times in power backup mode than more flow than I actually need. It's tough to beat the 28W OR2500 uses for my return ( measure on a watt meter not the rated listing ).

rihanssu · 10-30-2006, 06:04 PM

david, wouldn't the water lvl be low and he would get alot of noise with a slower pump with that much drain?

zryder · 10-31-2006, 06:23 AM

I have a 125 display with a 55 sump/fuge, external skimmer and I am running 2 mag 7's, and love it. I also have it plumbed so one of my mag 7's can be switched to a closed loop. I really like this idea, and for your tank, you will be very happy with 1 mag7. they are reliable, quiet, and cheap. Currently my 2nd is in closed loop mode, and I have no problems with that.
Also, your water level really wont change that much, it wont go below your overflow, and even with 1500gph it wont be more than a half inch higher.

2 1.5" drains sounds like a bit much though.. I am using 1 1", and it keeps up with both mag7's. what I would do is cap 1, make a standpipe for the other, put a ball valve to throttle flow, and call it a day.

David Grigor · 10-31-2006, 10:49 AM

Quote:

Originally Posted by rihanssu

david, wouldn't the water lvl be low and he would get alot of noise with a slower pump with that much drain?

No just the opposite. Less flow gives your more room for error and less taxing on the drain means less noise not more. IMO: Durso standpipes are a must regardless, less flow is less bubble mixture which means less noise in your sump. I don't get what you mean by water level low. Sump will always equal out to whatever the flow is. If you means the flow doesn't ride up as high on the overflow, that is good, gives you more room for error. I have always used canopy that overhang the top edge to where you never see the top of the water anyhow so irrelevent.

IME: You always want 2 drains if at all possible. If nothing else as a backup in case something happens with blocked or partially blocked. In my 320g tank, I once had a partically blocked overflow line and didn't notice for several weeks, no problem because the other one alone could keep up. With only 1 overflow, you will notice the hard way.

rihanssu · 10-31-2006, 11:14 AM

yeah what i was talking about was the water lvl not getting high on the teeth of the overflow.