how to match over flow with pump

[eyft23]

oh thank you for your answers. well my tanks are both 125gal. the head height will be no more than 5 feet for one and about 2 feet for the other one. my tanks are stacked above each other. i wanted to make a w/d for each, or could i make i wet dry for both.
the overflow that i want to make is from the diy section from MFK. in the thread they say each overflow with 1" pvc will flow about 600gph.
Bud8fan thanks for letting me about controlling the overflow, doesn't controlling the output of the pump somewhat break it faster or is it ok to control the output. the reason i ask is because i have read that by doing so you might do something to the pump.
by the way here's the diy overflow that i want to make:
http://www.monsterfishkeepers.com/forums/showthread.php?t=15733&highlight=diy+w%2Fd
from what everyone has said its great especially when the power goes out.
i think that i'll make a (1ea)1 1/2" overflow which should give me 1300gph and a mad drive md12 which should give me 1200gph for the pump. what do you guys think? or should i go with (2ea) 1" pvc which should give me about 1200gph?
and again thanks for all the help. i just dont want to screw up anything.

 

[vamptrev]

what u do is... oversize ur pump! valve off ur pump so it goes back to the tank and back to the sump. add a ball valve on the return back to the sump...

now u can adjust the flow to the tank and keep ur sump stirred... (without damaging ur pump)

 

[zennzzo]

Using a valve on the outlet side of your pump is just like adding Head or height...If you pump quits pumping water at say 15', at 14' it will be just a small flow, same as if you were to close a valve...

What is correct is,
you shouldn't put a valve on the intake side and starve the pump of water...that's what wears them out because they will tend to run dry because of starvation or what's referred to as cavitation in the pump...

 

[zennzzo]

I think 2 x 1-1/2" Overflows and your Mag 12...

 

[eyft23]

will my mag 12 keep up with the 1.5" overflows? because each overflow does 1300gph and the pump only does 1200gph total. so thats 2600 gph for the overflows and only 1200gph for the return pump?
if thats ok i'll take zennzzo's advice and make 2 ea 1.5" overflows along with my mag12.
thanks again for the help.

 

[zennzzo]

will my mag 12 keep up with the 1.5" overflows? because each overflow does 1300gph and the pump only does 1200gph total. so thats 2600 gph for the overflows and only 1200gph for the return pump?
if thats ok i'll take zennzzo's advice and make 2 ea 1.5" overflows along with my mag12.
thanks again for the help.

you need to realize something about the "OVERFLOW" system....

the pump is what dictates what has to be evacuated from the tank...
the only water your overflow has to be able to handle, is the water, your pump puts into the tank...,
the more water you pump into the tank, that much has to overflow...it either goes over the side or out the "OVERFLOWS"

this is the reason you oversize the overflows...

If the pump stops pumping water (power outage) the water will drain from the Overflows till the designated level is reached, then stops overflowing. "All stop water"


Power comes back on...Pump starts up, pumps water into the tank, any water above the overflow drains into the overflow...simple when you get the jest of it actually...

 

[eyft23]

you need to realize something about the "OVERFLOW" system....

the pump is what dictates what has to be evacuated from the tank...
the only water your overflow has to be able to handle, is the water, your pump puts into the tank...,
the more water you pump into the tank, that much has to overflow...it either goes over the side or out the "OVERFLOWS"

this is the reason you oversize the overflows...

If the pump stops pumping water (power outage) the water will drain from the Overflows till the designated level is reached, then stops overflowing. "All stop water"


Power comes back on...Pump starts up, pumps water into the tank, any water above the overflow drains into the overflow...simple when you get the jest of it actually...

damn see i knew someone could actually help me out with this. thank you very much zennzzo. i knew nothing about these overflows and how it actually works, but this really does put into laymens terms. especially for me. thanks again.
i guess i'll go for my original plan of putting 2ea 1.5" overflows for my tank and use the mag12 to pump it back into the tank.
thanks again for the lessons.

 

[zennzzo]

damn see i knew someone could actually help me out with this. thank you very much zennzzo. i knew nothing about these overflows and how it actually works, but this really does put into laymens terms. especially for me. thanks again.
i guess i'll go for my original plan of putting 2ea 1.5" overflows for my tank and use the mag12 to pump it back into the tank.
thanks again for the lessons.

Great choice of sizing!...
You are certainly welcome ...
If I can be of anymore assistance just ask, I'd be glad to share what I know...