GPH conversion

[180large]

I have little giant 4 mdqx-sc pump rated for 1225 gph @ 3' I am planning to put it my basementapprox. 10' in height. Does anybody know what the gph will end up being is this pump to small? I have e-mailed customer service at little giant they say it will be 7.1 psi i have no clue how to convert psi into gph or if it is even possible.:eek2:

[Bruddah Chrispy]

Did you try the Head Loss Calculator (http://reefcentral.com/calc/hlc.php) on the homepage?

[180large]

Brudd i dont get it??? I must be a little slow I cant figure that thing out.

[180large]

I was hoping to find out the gph after i ran my pump up 10 feet or so

[Wazzel]

psi does not convert to gph. psi is pressure and gph is flow.

[180large]

is there any way to figure gph/ flow at 10' of vertical length thanks for reply wazzel

[mhurley]

I'd ask Little Giant for a performance graph on their pumps. I poked around their website and couldn't find any. Tell them you need GPH or GPM, not psi...that's useless.

Ball park guess..you're going to lose more than half of the GPH. That pump shuts down at about 24' of head, figure half of that is your vertical lift and then a few elbows here and there, you're going to be well below 600 GPH if I had to guess.

Mike

[Wazzel]

Here is a copy of the pump cureve.

http://reefs.org/library/pumps/pumps/lg_4mdqxsc.html

If you only had the lift to worry about the flow would be 800 gph @10 ft. You will have to figure in losses due to you pluming, like elbows, tees etc. A rough guess would be about 2-4 ft additional losses if you do you pluming correct. this would put you in the 600 to 400 gph range. For what you are doing I would suggest a iwaki 70. This would put you in the ball park of 1200 gph at 12-14 feet of losses.

http://reefs.org/library/pumps/pumps/iwaki70rt.html

[180large]

thanks alot. I will have to check into that website (reef.org)

[180large]

is that enough flow if i also add a closed loop system up at tanl level or will it damage the pump?

[180large]

oh i forgot it might not keep up with the water flowing down into the system. I would assume that falling down 10' it will be moving quite rapidly into the sump????? what do think?

[180large]

sorry for all the questions but i am trying not to spend to much$$$$$$ How about a mag 24 or 36 any thoughts on these pumps

[pyranha]

The water that flows into the sump from the main tank is directly proportional to the water you are pumping out of your sump and into the main tank.

With that much head loss, I would go for a pressure rated pump. Iwaki or Blue Line. I just picked up a BlueLine and they are pretty decent pumps. A bit less expensive than Iwaki. Also, it is not bad to go a little overill on the pump and valve it down. This will allow you to increase flow later if it is desirable.

[180large]

pyranha, are you saying that it will keep up?

[pyranha]

Yes. It kind of has to don't you think?
The water coming from your sump is going into your maint tank. It then overflows(via an overflow I am assuming) and then into the sump again. If you sht off the pump, the water will stop flowing into the sump because no water is being introduced, and thus not causing it to overflow.
If you find that the overflows will not handle the water coming in, you can use a dremel to widen the slots to allow for more flow.
I am not 100% sure, but I believe a standard AGA overflow will handle about 700-750 GPH.
This is also the reason I mentioned putting a valve between the pump and the main tank. This will allow you to regulate the flow into the main tank.

[180large]

alright let me know if i am nuts but i have like 4 pumps lying around my house what if i put 1 at sump level and another about 6' further in line to finish pushing the water??? Will this even do anything it sounds like it might help.

[pyranha]

I have never tried it, but I am going to go out on a limb and say it would most likely not work very well. You would either underfeed or overfeed some pumps. A better plan might be to sell all 4 pumps you have laying around and buy an nice Iwaki or BlueLine.