Return pump help.

Its a baffle set up. There are 3 baffles. Water goes over the first baffle under the second then over the 3rd. Does that make sense?

 

Keep the overflow plumbing as straight and fitting free as possible since it is gravity. The return can have fittings and bends since it is pressure assisted. Keep the restrictions to a minimum though and make sure you have someplace to break the connections like unions near valves and especially pumps for cleaning and maintenance.

Two returns gives you more water movement for better circulation but many systems have single returns too. I prefer two myself, one in each end pointing towards front center so they converge and create some random currents to help keep detritus and things stirred up and carried out by the overflow. I went a step further and installed an Oceans Motions Squirt Two Way current switching device in my return so it switches back and forth, end to end, mixing flows up even more. Between this and two Evolutions 1400 powerheads on a Reefkeeper Lite controller wavemaker function switching every 30 seconds the random flows are great.

 

Here is my sump about 9 years ago when I was building it. Notice the three baffles between the center/skimmer section and the return pump section on the left. water travels over the first, under the middle or second then over the third so it must physically change directions and give up the trapped bubbles in the process.



And here it is in the stand way back when:



That was 9 years ago and the pumps and skimmer have all changed but the sump has never once been out of the stand and is still operating just like it did then.

 

Ok cool. Looking at your pic is it better to have the skimmer in the center and the fuge off to the side?

 

I'm running a eheim 1262 on my 210gal dt and 75gal sump. Works great imo. I prefer to try to match my skimmers gph (sro3000) and stay with a lower sump flow if possible. I have mine T'd off to my fuge and I have two 3/4in returns and it does the job nicely.

Get some WP40'S for flow up top and don't worry about how the return flow looks in the tank.

 

I prefer the refugium on the far end since it does not need the entire overflow GPD, only a portion is teed over to the fuge off the overflow with a 1/2" line and ball valve. The center section gets the bulk of the flow.