How much flow ?

[Mandrake]

I have 120 gal. AGA with two 1" overflows,what flow rate will be going to sump? Can you suggest return pump size?

 

[bookfish]

That depends on how much column pressure you have against the bulkheads (i.e. how deep they are under the water) and also how much restriction the plumbing will create between the b-heads and the sump. Also, if they're at the surface level as overflows, if you use a strainer, that will slow it down as well.

 

[cindre2000]

Hey,

I set up the same type of tank as you. It has a Iwaki 20RLT and a Mag 7 for the returns. The flow is a little lopsided to the Iwaki but a little bit of fiddling with the return nozzel and getting the Iwaki side to send the water to the opposite side of the tank fixed the problem a bit.

The tank is set up on the pine stand so the pumps are only pushing water 4-5 feet, probably about 1000 gph, however, that is probably pushing the drains just a little bit since they are rated for 600 gph each. In fact, until I fixed the return nozzle on the Iwaki side, the Iwaki side drain was siphoning from too much flow.

Just look at the rating on the pumps for the distance you are sending the water and take into account any elbows in the pipe. I would suggest only going for maybe 1000 gph so you have a little leeway, you can provide the rest of the flow with powerheads or a closed loop.

The DIY forum is a great place for plumping questions.