Directionality of flow through sump

[ReefDreamz]

My sump will be located in the basement below and to the right of my display tank. Should the sump flow from left to right as in the first image or right to left as in the second image? Does it matter?

 

[bevo5]

I'm not an expert on any level.

But I'd say the closer your return pump is to the aquarium, the better. Gravity is going to do all of the work for the drain, so making it as easy as possible on your return will maximize the amount of water you're pushing through the system.

 

[Soren]

My sump will be located in the basement below and to the right of my display tank. Should the sump flow from left to right as in the first image or right to left as in the second image? Does it matter?

It seems like it should not matter from the sump perspective, pending what you are putting in your sump chambers.

+1 to @bevo5 on keeping return lines shorter so pump does not have to work as hard/need as large of a pump to overcome increased resistance of longer return lines.

 

[rob taft]

Bevo5 got it right. Try to minimize where practical, the length and number of fittings on the return side.

 

[Tbg299]

My sump will be located in the basement below and to the right of my display tank. Should the sump flow from left to right as in the first image or right to left as in the second image? Does it matter?

As long as the flow of water is being directed to and from the drain, refugium, reactor/skimmer/filter chamber, return section in order it is good.

 

[Gtinnel]

Absolutely what @bevo5 said. There is no reason to make the return pump work harder to get the water back to the display.

 

[Reefer Reboot]

Weeeellllll... let me throw out a couple of other details to think about. Pumps create pressure (via centrifugal force in this case) to push the water through the plumbing. That pressure is much greater than the pressure created by gravity running through the drain plumbing bringing water to the sump. The only difference in plumbing between the two above examples is in the length of the straight horizontal plumbing. As long as the horizontal plumbing has an internal dimension as big as the outlet of the pump it will have a very minimal impact on the flow. Yes, a little but not enough to be worrying about in real life. (Granted it would be optimal to go a size larger.) On the other hand, the drain line will not have the extra pressure from a pump and will also be subjected to dirtier water which may restrict (clog) the internal dimension of the pipe. I think it would be better to have the drain lines as straight down as possible, or in this case, with the least amount of horizontal plumbing. (45* fittings would be better than 90* fittings in this case.)
(I'm also assuming you are using a pump rated for the head pressure needed for this application.)
Okay your honor, I rest my case. ;)