Return manifold feedback please (with pics)

[chaostactics]

All 1" plumbing, the return pump is a reef octopus varios 6.

 

So #2 is an automated (on/off) ball valve. I will be able to use an auto feeder to dump food into my return area to feed the tank via return pump flow, after the ball valve shuts off flow to the rest of my manifold (to keep food out of my reactor and skimmer feed, the return pump will also dial back in gph at this time as well since its not running the whole manifold). 

 

#1 Is there my return pump feeds the system. It tees off immediately to the left is the reactors, skimmer feed, and an aux ball valve for possible future applications.

 

#3 is the feed return to the tank, there will be a ball valve inline with the return to create back pressure to feed the manifold if necessary.

 

#4 Aux ball valve for furture expansion. 

[chaostactics]

Also, thinking about using the pvc all in one glue. Any reason i shouldn't do that?