PVC Manifold Question

I have 2 reactors now. I made 3 just in case I add something else or I can use it for water changes. The manifold is strictly for reactors/other equipment.

 

Will this work?

 

I drew this up real quick to show my new plan.
I might have to put a ball valves on the return lines to make them the same flow but same design concept.

 

DBO: thats how I would do it. add a gate/ball valves on the returns to help get even flow from all three.

 

I agree with plumbing the manifold before the return piping back to DT, and you might also want to replace the ball valves that go to the media reactors with gate valves ( they are easier to fine tune)