Drain capacity?

[fs40reef]

Hello All,
I am getting ready to drill my tank and plan on two drains and two returns. My question is how large should my drains be? I have a 70 gallon tank and am running it with a MAG 12. Will two 1 1/2" bulkheads do for the drains or do I need to go larger?
Thanks,
Will

[corruption]

I would go larger... 2 1.5" drains will net you near 1400-1500gph -- while its over your expected return flow, its only over that in optimal conditions. As time goes on, that will change... I'd go with 2" or 2.5" -- can never have too much available on the drain side, as the actual amount traveling your plumbing is entirely dictated by the amount of return flow coming from the sump.. :)

Another option would be to add a third bulkhead @ 1.5" -- this would give you some redundancy as well..

-Justin

[jroescher]

Each drain should be able to handle the overflow on it's own. If for any reason a drain quits or clogs, the remaining drain will still handle the flow.

[z28pwr]

Two 1.5 drains for a Mag12 is a piece of cake. A single 1.5" drain can handle a Mag 12. I have four 1.5 drains on my tank and push close to 1300 GPH through each with no problems.

[jesserettele]

I would go larger... 2 1.5" drains will net you near 1400-1500gph -- while its over your expected return flow, its only over that in optimal conditions. As time goes on, that will change... I'd go with 2" or 2.5" -- can never have too much available on the drain side, as the actual amount traveling your plumbing is entirely dictated by the amount of return flow coming from the sump.. :)

Another option would be to add a third bulkhead @ 1.5" -- this would give you some redundancy as well..

-Justin


How is GPH calculated for drain size? I have two drilled 1 3/4" holes on a 75 gallon. You have a 75 gallon I see, what are you using for drain?