Matching pump h.p. to well point size and length?

**ron in sc** · 06-04-2007, 12:25 PM

Do I need to match a new well (shallow well, 20ft.) to a particular horsepower pump motor?

The well point is 2" diameter and the screen part is 5 ft. I don't know the water output yet. I did hook it up to a 2" gas powered trash pump to see what I'd get in the way of sediment and the like. Really no sediment just clear water.

How many hp pump should I get?

**speedbump** · 06-04-2007, 12:36 PM

You need to use a five gallon bucket and do a test with the use of the trash pump to see how many gallons per minute this well will produce. Then we can size a pump.

bob...

**ron in sc** · 06-04-2007, 12:57 PM

You need to use a five gallon bucket and do a test

I don't have the trash pump anymore. I rented it for a day to use if a couple of foundations I had dug flooded due to heavy rain.

I don’t know if this is any help or not but I have one of those 1 1/4" PVC well points with a 4 ft. screen on the other side of the house. It puts out 6 gallons per minute at with a Myers 3/4 hp. Model #HJ75S, attached to a Wellsaver tank model #LPT7H

**speedbump** · 06-05-2007, 05:57 AM

I would think if these wells are identical, you can expect to get the same from both.

bob...

**ron in sc** · 06-05-2007, 10:47 AM

They are not exactly identical since the new one has a 2" pipe that has a 2" well point with a 5' long screen as oppose to the other one which is an 1 1/4 pipe that has an 1 1/4" screen that is 4' long.

**sammyhydro11** · 06-05-2007, 11:09 AM

Ron,
after every well is installed the well needs to have a 4 hour pump test performed in order to determine its yield. It would be unwise to assume that one well produces the same amount of water than the other. Correct me if I'm wrong but i thought we have been through this before. Isn't the well in the basement and you couldn't use the gas pump inside because of the exhaust but if you pumped it from the outside the extra height in elevation would prevent the pump from working?? You need to rent an electric jet pump and perform a pump test to determine the yield then you size your pump and the demand based on those results .

SAM

**speedbump** · 06-05-2007, 12:12 PM

I based my assumtion on the fact that the material must be not very pourous since the well produced a very small amount of water. That would take away the difference in screen size and length since they are both capable of a larger yield if the water were available.

bob...

**sammyhydro11** · 06-05-2007, 12:50 PM

Ron,
I'm sorry about the comment i made about the whole gas pump thing. I believe i may have mixed you up with another person that was in an almost identical situation. Anyway,get a pump test done and post your results.

Bob,
i think there are too many variables involved with this one to assume one will produce the same as the other. Your right, if the materail was porous enough those screens would have no problem allowing plenty of water through them.

SAM

**ron in sc** · 06-05-2007, 01:20 PM

Ok, I may just disconnect my pump form the operating well and temporarily hook it up to the new one and see what it produces.

**Gary Slusser** · 06-05-2007, 02:51 PM

I've always sized a pump by the gpm the building needs at the high pressure setting used etc. and then found the horses to git'er done... and the gpm needed should have been known before the well was done and if the pumping test doesn't deliver the gpm, then the 'driller' should be told to keep digging. Or you'd have to re-evaluate the gpm needed by nailing a bathroom door shut etc.. But here we may be only watering posies so....