Plumbing advice please

[Ab129]

Still working on setup of my 75 gal
I went with the varios 6 pump from reef octopus for my return. The pumps outlet is 1 1/4 inches and I planned to use 1 1/4 inch pipe up to the tank.
Just watched a marine depot video where they install this same pump and use a reducer down to 1 inch pipe for the return.
Now I am wondering if I should go with the 1 or 1 1/4
What difference would it make?

 

[shifty51008]

you can reduce the output of the pump just don't reduce the intake side of the pump

 

[mcgyvr]

It could just mean a reduction in total possible/achievable flowrate.
Its fine to do so though..

 

[Ab129]

It could just mean a reduction in total possible/achievable flowrate.
Its fine to do so though..

My only concern is that if I bought too much pump for my system and use the 1 1/4 will the flow rate be too much for me to Balance with the draining capacity even at the lowest flow setting.
Herbie system 1 inch drain is what I will be using.

 

[miPapareef]

Do you plan to run a manifold and use some flow for the skimmer and reactors? If it just for the return to the tank, that's a bigger than needed pump for that tank. But it's variable speed with 5 set points on its built in control so you'll be fine.

It's typical to be in the 5 times water volume for the flow rate through a sump. With all the plusses (sump, plumbing) and all the minuses (sand, rock) you are still going to be close to 75 gallons of water. So that's about 375 gallons an hour as a target flow rate. Hare here's the flow curve for your pump.

Your head height is the distance from the display tank water level to the water level in the return section of you sump, and add the restrictions due to plumbing. There are many online calculators for this. Typically is 4 feet of head. So on your pump curve it shows ~1100 GPM.

End result you have a great, quiet, variable speed pump that if you run on the 2nd or 3rd level you'll be in the ball park. And don't worry at all about using the 1" return line. Good luck with the build.


Sent from my iPad using Tapatalk

 

[Ab129]

Thank you!
I know I would be ok with the 1 " but I have already dry fit everything with the 1 1/4 and was wondering if I would be ok with that or if I should replace with one inch
Don't know anything about manifolds and reactors lol!
Complete newbie

 

[miPapareef]

The 1 1/4 return works fine.

Your 1" herbie drain will be the limiting factor in the system. Lots of variation in what that flow rate will be mostly due to the entrance restriction of the screen and turbulence of the entrance water. Theoretically a 1" pipe at full siphon with at least a 2 foot drop is more than capable of handling your pumps capacity, but this is the real world where algae and snails and wave pumps all cause reductions to the theoretical rates. See here for a no loss calculator.
http://www.calctool.org/CALC/eng/civil/hazen-williams_g

You will want to do some plumbing tests with your single 1" herbie drain to make sure your pump can't overwhelm the main drain OR emergency drain should the pump get accidentally turned on full.

 

[benjammin03]

So it doesn't hurt the pump to limit the output?