I just got a 58 gallon Oceanic tank and I was wondering how much water the overflow can handle. The return pipe is one inch. Please let me know, thank you
You told us what size the return pipe is. What we need to know is what size the overflow pipe is. NORMALLY, the overflow is 1" and the return pipe is 3/4".
Rick, without knowing the size of the overflow, it's impossible to say what pump would be adequate. Besides, I'm guessing the two lines (overflow/return) are reversed in the plumbing.
Also, what is the height from the return pump to the top of the tank?
With those two pieces of the puzzle we can give you a much more accurate recommendation for pump size.
Assuming your pump is approx. 4' below the rim of the tank, you can easily use a Mag 7 run wide open for your return. The 4' of head will drop the output from the Mag 7 from 700 gph @ zero feet of head to 475 gph @ 4' of head pressure.
You might be able to get away with an Eheim 1262 also. At 0' of head it delivers 900 gph. But at 4' of head it drops to approx. 600 gph. Very close to the limit of the overflow so you might need to dial it down just a fraction.