New plumbing design for two tanks and sump.

[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.