Increasing the flow of overflow box.

Hi guys, I'm running a Eshopps Nano(200gph) overflow on my 20H tank. I'm also using a Maxi-jet 900 as the return pump. The overflow and return are working fine, but the pump is throttled way back. The overflow has a 3/4" bulkhead and a 1" u-tube. I'm thinking that the restriction is in the u-tube. Would it speed up the flow if I lowered the skimmer box inside the tank? Thanks guys.

 

get a thicker u tube or ad a second one

 

I was thinking about adding a 1/2" u-tube but does it matter where the tube siphons into on the back of the overflow? There is no room in the skimmer box for a larger tube. But I can maybe add a 1/2" tube on the other side of the skimmer box but it would siphon into the side where the bulkhead is(not the side where there is a wall in between.

 

the thing with that would be the one that goes to the other side of the divider could lose its siphon in that case, maybe look into keeping the same skimmer box and getting a larger back portion of the overflow

 

How straight/long is your drain hose run?

Is this a new development, or was it slow from the start?

Have you checked to be sure that there isn't a snail in the drain line?

How deep is your drain line sitting underwater in the sump?

Is there a bubble in the "crook" of the U-tube?