GPH Question

[jjboods]

I heard from All-Glass. The overflow in my tank is rated at 600gph. The head is about 4.75 feet. I read somewhere that the pump should run no more or less than 100 gph difference from the overflow. I think I'd prefer the pump to push more than 600 gph rather than less than 600 gph. Would this be okay? I can't seem to find a pump that pushes near 600 gph at about 5 feet of head. They are all much more or much less.

 

[fedukeford]

A little more is ok, you could always just slow it down. Im pretty sure a mag 9 would push somewhere near 600 at 5'
Feduke

 

[jjboods]

The Mag 9.5 is rated at 700 gph at 6 feet. That would defeinitely be too much for a 4.75 foot head.

 

[rhino]

Most people have a ball valve after the pump to correct the flow.

 

[jjboods]

I'm sure it isn't a big deal, but I don't like the idea of restricting the gph from the pump.

 

[cmaxwell39]

Instead of just having a ball valve to restrict the flow, you could put a tee in the return line and run that tee back into the sump with a ball valve on that to control how much is going back into the sump and how much is going back to the tank. This way the pump would be wide open and you are just diverting the extra pump capacity. If your pump pushes more back to the tank then the overflow can handle you will end up flooding the tank because the extra water will have no where to go but over the top. You have to return slightly less to the tank than the overflow can handle.

 

[fbm]

I have an AGA overflow rated for 600 gph. My pump puts out 725 rated at the 4 foot head that mine is at. My overflow has no problem whatsoever keeping up with it. I even added a 5 gallon bucket of saltwater to the overflow to see how well it would keep up. I poured the bucket in over a period of 20 seconds and the level in the overflow still didn't rise. So either the overflow can handle more than 600 gph or the pump rating is way off. Either way I think you will be fine with alot higher flowrate.

 

[jjboods]

I ended up getting a Quiet One 3000. The chart looks like it rates at 600 GPH at 4' and about 425 at 6'. I figure I should get somewhere around 525-575 at 4.75'. I did more research on my Oceanrunner 2500. I was probably only getting 400gph.