Sump Pump Question

[CHEMCHEF]

I am setting up a RR. 72 bowfront.
I will be using the megaflow overflow kit, a 20 gallon long sump refugium, aqua ev180 protien skimmer (in Sump) with a mag 7 for skimmer.
I am curious what pump (GPH) i will need for the return
I have Been Told Mag 7, but i wanted to make sure this is accurate

 

[FREEZE]

that will work fine.

 

[CHEMCHEF]

this is my first sump build so i guess my next question is.
Can i put the feed pipe from the overflow to the sump below the sump water line, for noise puposes or is this a no no

 

[FREEZE]

that is not recommended. you can have issues related to the back pressure that is created. try positioning the feed pipe just above the water line, and test the noise level. I use a filter sock there - you might opt for this for mechanical removal purposes. Sometimes noise will be related to how much water volume is moving through your sump - and this can be controlled by adding a ball valve between your mag 7 return pump and the return entry point in your main display. hth.