Head loss question.

[Jackie Blue]

I know there is a head-loss calculator here but I have a hard time believing that my plumbing idea will take the mag 12 I am looking at buying from 1100 gph at 4 ft to around 726 gph. I have two returns on my 75 gal tank, one on each side of the tank. I am looking at connecting a 3/4 inch scwd, with the goal in mind of not having any power heads in the tank. Each return will Y off using ball fittings with a total of 4 return nozzles. I have some SPS frags sitting at Edward Smith's house, (my tank busted a seam). 726 GPH is not enough turnover do I need to bump it up to the next mag (mag 18 I think)?

I don't want to believe that I am going to lose around 4gph because of plumbing.

Any Ideas?
Jack.

 

[sjm817]

I doubt you will have that much with a SCWD. Whats the max capacity of the overflow?

 

[Jackie Blue]

1500. The overflow calculator makes no sense to me, for instance when I put in my plumbing scheme with some 90 degree bends replaced with 45 degree bends, the GPH came out to be 2 gallons an hour LESS.

 

[Jackie Blue]

How much does a one way valve restrict flow?

 

[birch03]

I think it was about 10% or so