Question for PVC and bulkhead experts...
I need some advice on plumbing a pre-drilled Oceanic 57 gallon rimless tank. The tank has two 1.75" holes for 1" bulkheads located roughly in the middle of the tank and I plan to run my tank outflow and filter inflow through them and to keep the rim of the tank completely uncluttered. I'm aiming to keep mechanical stuff as invisible as possible once the tank is grown in. (I'm suspending a DIY LED fixture above the whole works to complete the effect.)
I've attached a picture of my current plan for setting up the works in the tank. Viewed from the back of the tank, you see: (1) a straight pipe up from the "tank outflow" bulkhead connected to a basic strainer fitting, and (2) a simple manifold made of 1/2" PVC that carries flow from the "filter inflow" bulkhead to some loc-line fittings set up on either side of the tank.
Below the bulkheads I had planned to put in two 1" ball valves (as shown in the picture) but they are so gigantic I may just put reducers on the bulkhead and use 3/4" valves instead. I'll glue these to hose barbs and do flex plumbing to a canister filter (probably an Eheim 2217, though I'm worried circulation will be inadequate), Hydor inline heater, and inline CO2.
None of this is glued up yet, so I'm looking for suggestions for improvement. My main concern right now is keeping the overall profile of the inflow manifold down low enough so that everything except the loc-line will be covered by substrate. 1/2" PVC fittings are pretty bulky and the necessary bends force the loc-line to come up fairly high off the bottom and far from the back of the tank--I may switch to 1/2" CPVC inside the tank to try to address both problems. Any other ways to address that problem?
Alternatively, would I be better off simplifying this by simply having a single loc-line "Y" fitting come up from "filter inflow" bulkhead? I worry that this will not spread flow around the tank enough...