Need some plumbing opinions

[WhatCouldGoWrong71]

I’m adding a second sump to my system. I’m also adding a larger frag tank. I’m not comfortable with the close tolerance I have with capacity and Murphy is a real person. So I had a second sump built. I’ll be pulling water from my main sump via a 1” feed. It will feed the frag tank flow from the frag tank to the new sump. Connecting the two sumps are 2 - 1.5” connections that will equalize the water height in both sumps. The water will simply flow to the other sump. Both sumps are identical height and are sitting within 1/8” of each other. Yes those are Haywards, I’m addicted to them below the water line.

My question is this. I prefer the first option (first picture. This keep the pipes as far from possible for getting hit for some random reason. However the other pipe will be below the inner pipe. Now, I know that if the other pipe were to be clogged, this pipe would easily equalize the two sumps. My curiosity is, does it matter at all, the water will have no resistance at all, and it will flow equally. Or is there something at play that I am unaware of due to the circumstances?

I’m using the extra union in the second open in case there is a leak in the threaded connection to the bulkhead, I can tight it without restriction a glued pipe would create.

Flame away! lol

 

[UncommonSense]

An interesting layout, but “over/under” looks good to me!
— maybe add a strainer to the “under” plumbing bulkheads on both sump interiors? Assuming both pairs of bulkheads on both sumps are level; detritus can accumulate in the “under” plumbing… it should all be fine silt; unless a big chunk of macro algae, livestock, etc was to get trapped in there!

Frictional flow loss through pipes and fittings is a factor you may have overlooked; but in the case of dual 1.5” crossover plumbing/1” feed; it’s practically irrelevant!

 

[WhatCouldGoWrong71]

Thanks. Great point about the detritus. I’ll have to add it to the husbandry list when I do sump maintenance. I do have strainers going on all 4 ends. Mostly to keep snails out. The over under is what I prefer. I don’t have to waste 45s either I’m going with just 90s. I’m adding another roller which will be on the frag tank, so that makes 3 and about 85% of each system turn makes it through a roller, but I feed redunkulously heavy so it’s amazing how much detritus builds up.

 

[UncommonSense]

Thanks. Great point about the detritus. I’ll have to add it to the husbandry list when I do sump maintenance. I do have strainers going on all 4 ends. Mostly to keep snails out. The over under is what I prefer. I don’t have to waste 45s either I’m going with just 90s. I’m adding another roller which will be on the frag tank, so that makes 3 and about 85% of each system turn makes it through a roller, but I feed redunkulously heavy so it’s amazing how much detritus builds up.

you can probably just plug the “under” bulkhead inlet on the upstream sump with your hand, or whatever’s convenient while the return pumps are still running… wait 10-ish seconds, unplug. The sudden surge of water should flush silt out of the pipe nicely if performed as a regular quick step in your maintenance routine!

Edit: you’ve got ball valves, just use those to surge water through your crossover pipes!