Head pressure calculations

[Eric23]

Can someone help me calculate my head loss ? I have 62 inches of one inch pipe, that includes a manifold with 2 90's and 4 45's plus the 90 that's hooked up to the return nozzle, I also have a 1/2 outlet hooked up to the manifold that's feeding an algae reactor about 2 feet away. I don't know if I have to calculate all the 1/2 tubing and the reactor ? Below is a pic. The second 1/2 outlet on the manifold used to feed a carbon reactor that I no longer use. I've heard people say that every 90 degree elbow is equal to a foot of head loss but I don't know ?

 

[Eric23]

Pump I'm using is a reef octopus varios 6

 

[Sod Buster]

Yes. Every 90 is equal to one foot in height or head. That is the decided formula years ago from somebody. That pump will almost laugh at that height. 60" vertical is 5 feet

 

[Eric23]

I know the pump will still move water at this height I'm just trying to get an idea of how much ? I don't know if I should be keeping at full speed or somewhere lower ? According to the chart from reef octopus if I have 5 feet of pipe and 3 90's that's about 8 feet of loss which gives me 800 gph at full speed which is exactly what I want but I had been running it at half power forever thinking I was getting way more flow

 

[Sod Buster]

What are you trying to accomplish with this flow to the display?

 

[Eric23]

I'm not trying to accomplish anything special. I'm just going by the manufacturers recommendation . It's a reefer 350 and the recommended flow is 790 gph

 

[rockskimmerflow]

You'd have to measure your drain flow back into the sump for a certain interval of time then calculate it for gph. There's no way to look at that assembly and even close to accurately figure out how much flow you have going to the tank based on tubing run length and the bleed off from the manifold.

I'd be shocked if a Varios 6 was actually pushing 790gph through the tank with the head loss and manifold bleed off in your plumbing setup. May be possible but I'd be very surprised.

Not that you should freak out about it if it's not. I think most tanks can run on a pretty wide range of turnover rates provided you have ample in-tank flow.