Return pump head calculation question

[BC1906]

I'm building a 180g tank and I am looking at return pumps. My tank has dual overflows in both corners. When I calculate the head height do I add the length of all the plumping? For example, if both of my returns are 4ft from the return pump would I use 4ft for my head height or would I use 8ft since there are 2 returns?

I am thinking of getting the reef octopus varioS-6. My drain pipe is 1.75" and my return is 1.25". Would this pump be enough?

 

[M3ace9]

Yes you would need to use the total length of both returns to calculate the ending result of flow. The varios 6 will not be enough flow for your tank because it loses a lot of flow from head pressure. The varios 8 might be enough but have not had a chance to check it out. IMO I would go with a sp6 or L1 to get at least 1000 gph of flow as a result.

 

[psirex]

Head height is usually based on vertical runs, horizontal not so much but yes if doing the calculation\math you would include both return runs.

 

[BC1906]

Thanks! I was originally looking at the vectras. I guess I didn't realize that I would need over 2,000gph. I was thinking somewhere around 1,500 but I guess going bigger will not hurt and I can adjust it if needed

 

[psirex]

The general consensus is 10x the display size (at least it used to be)......

 

[BC1906]

The general consensus is 10x the display size (at least it used to be)......

And that's not including head height right? So automatically I would need 1800gph not including head height?

 

[psirex]

Correct

 

[Rick.45cal]

Get a Royal Exclusiv Red Dragon Speedy 3 pump, they are dead silent, DC controllable, and unlike other DC pumps they don't suffer as drastic of head loss. I think it is the increased torque of the brushless motor they use. They aren't cheap, but the one I picked up recently to replace two sicce 5.0 as returns is a beast. I'm more than impressed with the 150watt. There's no way I will be able to use it to it's full capacity in my situation.

Just FYI, if you do order one, they don't tell you, but they include the union adapters for our non metric PVC with the pumps.