Overflow/powerhead ?

[cjtabares]

The tank is an 100gal long (72"x18"x17") it is acrylic so i was going to add my own overflow. I was going to drill 4 holes to going to my sump/fuge and 2 returns. I was thinking this because the tank was so long i wanted more returns dose that make sence? If so where should i point the returns and how many powerheads would i need and where? Thanks for any help oh and it will be a reef tank.

A pic of what i was thinking

[cjtabares]

The reason i wanted 2 returns was so i could point them in 2 diffrent directions

[Reefscape]

I dont see any issues with having two returns, as long as they balance out the over flow...When working out the overflow speed, a 1 inch bulkhead is about 600gph flow..you are wanting 4, so, your overflow speed is going to be about 2400gph after taking head height into concideration...Your return pump wants to be about the same as that, but not more else that will cause an inbalance on the plumbing...

Hope that helps..

Niko

[cjtabares]

thanks sorry i said that wrong 2 holes are going to go to my sump/fuge and the 2 outside holes will be returns so if i have 2 1'' going to my sump that would be 1200gph right? with the returns should i use 2 600gph pumps and keep the plumbing separate or one 1200gph pump and split the plumbing right befor it returns to the tank? I was thinking of using 6 hydor koralis 3, with each at 800gph plus the returns it would be 6000gph is that to much?

[Grins]

It won't be too much but it also won't be that much either once you account for head loss. I don't even include my return pump in my flow figure.

[cjtabares]

ok so that would be just the 4800 from the 6 powerheads should i go with 6 of the koralis 4 1200gph making it 7200gph or 4 of the 3s and 2 of the 4s for 5600gph? sorry this is kindof a long tank for the gallons i am haveing a hard time thinking of away to have no dead spots should i take that in to account and go over the recommended 25x per hour for reefs, can there be to much flow?

[vorlx]

ok so that would be just the 4800 from the 6 powerheads should i go with 6 of the koralis 4 1200gph making it 7200gph or 4 of the 3s and 2 of the 4s for 5600gph? sorry this is kindof a long tank for the gallons i am haveing a hard time thinking of away to have no dead spots should i take that in to account and go over the recommended 25x per hour for reefs, can there be to much flow?

If I were to do it in a 6ft long tank I would split it up with a more chaotic flow. Maybe 4's on the end and then maybe 2's or maxi jets along the back.

You could always start lower and work your way up as needed once you have identified dead spots. It always varies and you never quite know how it's going to turn out. Flow is really dependent on what you are keeping. Some things like high flow, some like low flow, some like a wavelike flow. I have 2 4's on each end of my 75g and have had 600gph extra from a closed loop on top of the approx 500-600gph from my return if you want to count that. 3000+ in my 75 (40x+) isn't much at all to be honest. There are so many different ways you could do it.