Return Piping questions

[Greg Depo]

Hello,

I recently acquired a new tank and it has two 1.5" bulkheads drilled into the back. One will work fine for my internal overflow box. The other I'd like to use for the return however my 1250gph return pump has a 3/4" outlet. My question is what would be the best way to get that 3/4" outlet to the 1.5" bulkhead? Bushings? If so do I increase the return pipe immediately out of the pump? Or should I run the 3/4" pipe all the way to the bulkhead and then increase the diameter to 1.5"?

I've done some research on this and haven't really found the best solution.

Thanks guys!

 

[Flippers4pups]

Hello,

I recently acquired a new tank and it has two 1.5" bulkheads drilled into the back. One will work fine for my internal overflow box. The other I'd like to use for the return however my 1250gph return pump has a 3/4" outlet. My question is what would be the best way to get that 3/4" outlet to the 1.5" bulkhead? Bushings? If so do I increase the return pipe immediately out of the pump? Or should I run the 3/4" pipe all the way to the bulkhead and then increase the diameter to 1.5"?

I've done some research on this and haven't really found the best solution.

Thanks guys!

Increase to 1.5" straight out of the pump.

 

[Hemmdog]

If the tank is drilled for a 1.5 look into an external overflow box. It gives you so much more room inside the tank and eliminates dead-spots from internal overflow boxes.
How many gallons is the tank? What pump is it that you are using?

 

[Greg Depo]

If the tank is drilled for a 1.5 look into an external overflow box. It gives you so much more room inside the tank and eliminates dead-spots from internal overflow boxes.
How many gallons is the tank? What pump is it that you are using?

The tank is 75g. I actually already bought an internal very low profile overflow box however I'm always willing to listen to any ideas. The pump I bought is a hydor seltz d varia flow. The head pressure according to my math is roughly 3.5ft. Increasing the pipe diameter can actually help the head pressure correct?

 

[shoggoth43]

Assuming it's not specifically a pressure related pump you're unlikely to see 1250 GPH unless you're using at least 1.25" plumbing. Go 1.5" from the pump to the bulkhead for the best flow and you can pretty much ignore the couple of fittings in the way and just use the head height on the pump curve to figure out your flow.

 

[Greg Depo]

Assuming it's not specifically a pressure related pump you're unlikely to see 1250 GPH unless you're using at least 1.25" plumbing. Go 1.5" from the pump to the bulkhead for the best flow and you can pretty much ignore the couple of fittings in the way and just use the head height on the pump curve to figure out your flow.

Makes sense. I may start a new thread for this but if I go 1.5" all the way to the bulkhead what nozzle should I use on the inside of the tank? Not many options at that size and stepping it down defeats the purpose of having it that large in the first place right?

 

[shoggoth43]

You’ll lose some flow at the momentary restriction but not as much as if you used say 3/4” pipe the whole way vs 1.5” pipe and ended with a 3/4 nozzle.