Overflow size & Mag pumps

[michelle l]

I have searched through the forums and can't really find what I am looking for. Sorry!!
I am setting up a 125 gallon reef system, and my tank isn't drilled. I'm not willing to risk drilling it myself and nobody in my area will do the job, so I am going to have to use overflows on the back of my tank. I have a 55 gallon sump/fuge underneath the tank.
What size overflows will I need to get adequate turnover in my tank? What is the ideal setup for that? (One overflow, two overflows, three, etc.?)
I had sort of planned on using two overflows (one on each end of the tank) and run two Mag drive pumps to return water to the DT. What size pumps will I need to get adequate turnover?
Also, what is the ideal turnover rate for a 125 gallon reef? I had read that 25x is ideal, so that means I would need to circulate about 3200 GPH?
Thanks!!

 

[adamc1303]

I would go with 2 overflow boxes one at each end like you specified in the post, plumbed with one return pump. A cheap strong and long lasting pump that can be used is a mag 36 if you wana go submersibile. If not you can plumb the mag inline but people have said that they tend to leak and I have never tried it yet so I cant tell ya.

 

[michelle l]

Thanks!
Yeah, I didn't want to plumb inline. I was thinking of using two submersibles because then I could route the flow to each end of the tank instead of one strong flow to one spot. What size overflow boxes would you recommend?

 

[dogstar]

Each 1 inch size drain in an overflow will handle 600 GPH. Some boxes have two and best to get two boxes with two holes if you want that much turnover. That will give you an ability for 2400 GPH and a 19 X turnover and IMO that fine for most corals unless you want to keep alot of SPS ect. that can require more flow and then may need powerheads inside the DT to make up any difference in what you want. Or add a 3rd box.

 

[saltfan]

You can buy 2 OF with the capacity of (largest ones) 1600gph ea. OF lines are 1 1/4"

 

[coachklm]

my tank is drilled with 1.5" holes giving total 1300gph per hole/drain twoholes would make my drain 2600 total and a return pump of sequence dart finishes it up .

 

[saltfan]

Hmm, versus 2 CPR 1600gph OF =3200gph. Hmm, if I didn't have a drilled tank, and wanted max flow as possible, the overflows can handle more gph.

 

[toungetwster]

I have a 125 with 30 gallon sump; I use a CPR CS100 with a Quiet1 4000. I does a good job and I'm totally happy with it. I do use an external filter; (primarily for running carbon bags and such) , it's a xP3 Filster by Rena. That pump feeds the tank on it's own. I use 2 Seio 820's for random flow in the tank my corals are happy and have no problems with sump, flow, plumbing, coral heath, anything.