View Full Version : 265 gal with 1 1/2 drains = Way too much drain

03/18/2007, 08:33 PM
I am flowing pretty hard into a sumpwith 2 overflows at 1 1/2" and I wanted to tone it down a bit it splashing like a raging river ? I have 2 mag 18 flowing in at 3/4, do I put a valve on the 1-1/2 drains and return lines .


03/18/2007, 09:27 PM
Your return setup has a couple of issues.
1) 3/4" plumbing is far too small for a Mag18
2) Two Mag18 even restricted with the small pluming is too much return pump.
If you have the Mag18's plumbed with the correct size plumbing (at least 1.5"), you would have a ton more flow than you do now which would be even worse.

I'd lose 1 Mag18, and see how you like it. With the the small plumbing, the single Mag18 might not be too bad.

03/18/2007, 09:55 PM
You dont need two mag18's for return. Just use one pump and T it off. You might even have to throttle it back a little.

Calculate 3-5x turnover thru your sump.

03/18/2007, 10:45 PM
Then you have the other mag18 as a back up pump.

03/18/2007, 10:46 PM
2 Mag 18's defiantly seems like its overkill. Do NOT put anything restricting the overflows I've heard of people using ball valves on overflows and IMO its just asking for a clog and a flood.