New plumbing design for two tanks and sump.

[Douglas]

Here's my new plumbing design for incorporating my old display into my whole system. All three tanks (new, old, and sump, will be at three different levels of height. With the main display being in a different room. I didn't have a lot of people interested in purchasing my old display, so I'm going to keep it, and plumb it into the system. (will keep rock, and a predator). Looking for opinions to see if it'll work. Thanks.

[typezero]

I would run both tanks to the sump and have a separate return for both tanks. That way you can control turn over rate and avoid micro bubbles to the predator tank. Also consider if your sump can take the extra water and not overflow with both tanks being offline.
And get a super sized skimmer so it can keep the water super clean so the predator tank wont mess up the display reef tank water quality.

[KrazyKuch]

I agree with typezero, if you plumb it this way all the surface scum from your display tank will end up in the predator tank!!

[Fesso]

+1 on separate lines to each tank, on top of what has been mentioned dialling in your Herbie syphons will be difficult with the way you have it set up in the drawing especially with 3 reactors off a manifold.