Best way to plumb dual returns

[ReefSlice]

My new 150 gallon tank has dual 3/4" returns, and with the pump I'm going to be using (fluval sp6) having a larger output, my plumbing is starting to confuse me quite a bit. I plan on keeping the 1 1/4" plumbing from the pump to the return bulkheads from which they will go into locline, but what is the easiest way to reduce it at the bulkheads, and should I use flexible tubing for the first 18" to reduce vibration or just hard plumb the whole thing to cut down on using barbed fittings?

 

[tank o tang]

I would use all 4 bulkhead for drains and go up over the back for your return.

 

[Flippers4pups]

I agree with @tank o tang, one on each side as main drain and one on each side as an emergency drain. Return as a single and split into lock line on each side. I'm biased on this, as that's the way I did my current system.

 

[ReefSlice]

Sorry for the confusion, I have 3 dedicated drain holes via a 16" synergy overflow, so drains are not a problem, just trying to figure out how to work the plumbing from 1 1/'4 to 3/4 the best to minimize head loss and see what everyone thinks about using flexible tubing for part of it with barbs up to the hard PVC.

 

[Flippers4pups]

Sorry for the confusion, I have 3 dedicated drain holes via a 16" synergy overflow, so drains are not a problem, just trying to figure out how to work the plumbing from 1 1/'4 to 3/4 the best to minimize head loss and see what everyone thinks about using flexible tubing for part of it with barbs up to the hard PVC.

1 1/4 is coming out of the return pump? If 3/4 is coming out of the return pump up to the bulkhead, which is 1 1/4, just use reducers to get past the bulkhead and continue 3/4 into the tank. Very little head loss will happen. I would hard plumb everything pvc.

 

[cracker]

Flex tubing preferably black is good. Can we see a pic of these bulkheads? where are they placed?

 

[ReefSlice]

Don't have the tank yet but the two 3/4" return bulkheads are on opposite sides of the tank on the back panel. Output of the sp6 is 1 1/4 and bulkheads are 3/4".

 

[cracker]

1 &1/4 to 3/4 , hum That reduction would cut way back on flow passing thru. Would you consider capping off the bulk heads & running the returns over the back? This way You get max efficiency out of the pump. Have you put down money yet?

 

[drtrash]

Cunfusing the man, the bulkhead outlet is 3/4", so just run the 1 1/4 directly to bulkhead and reduce to bulkhead inlet. Since its a ac pump, small section of braided hose from pump to sump bulkhead id good, hard pipe the rest. You can run a loc
Ine nipple in tank or a 1" 45 reduced to 3/4" and screw into bulkhead

 

[ReefSlice]

I got the tank for a very good price so I took the returns that came with it, hence going up to such a big pump. I'm pretty sure it will still give me about 900 gph through the overflow which is plenty for me, just wanted to see what others thought. It's the two bulkheads on the back of the tank that are 3/4", the pump will be run in the sump.

 

[ReefSlice]

Would reducing the plumbing at the T help with head loss in this case or should I run 1 1/4 all the way to the tanks bulkheads? Anyone else running a similar setup?

 

[DCR]

I think you are likely to get 600-800 gph with the two 3/4" returns which I think would be OK for a 150, but you are wasting money on the larger SP6. You will get about the same performance from the SP4 because of the restricted piping. The SP6 really needs 1-1/2" piping to achieve its full capability, and it does not produce a lot more head than the SP4 at low flows. You will probably get less than 50 gph additional flow with the SP6 over the SP4.