I moved into a rural home which has a water well. I have no info
at all on what type of pump is in the well, or its age. All I do know
is that it is submersible, and it produces 15 GPM. The well guy said
the water level is at 60 ft. and the draw-down was to 75 ft. It is
only a 4in. well. Its producing a little very fine sand. It has a
20/40 pressure switch. THe well guy said it has only a 20 gal.
pressure tank, and he says I should replace it with a 50 gal. tank.
I plan to replace the tank with 50 gal as recommended soon, and I
learned that 20/40 pressure switches can be raised to regulate 30/50
by turning large nut clockwise. It already cycles for only about one
minute each time it comes on, so I know I need to go to a larger tank
before trying to raise the pressure. The only reservation I have about
this is with the pump. Is there any risk to the longevity of the pump
by going to a higher pressure once 50 gal tank is installed?
Don't think raising pressure will be a problem. Think my max is 60
Not sure you need the bigger tank unless the old one is bad. Also, if
your getting some sand or residue, would be a good idea to install a
No. The sand will be far more an issue on pump life if there's enough
you can see/feel it...the larger tank may exacerbate that problem
slightly by longer run times if it tends to produce more sand as the
well is pumped. If, conversely, the well characteristic is such that it
cleans up (altho that's fairly unusual I think) w/ time, it could be of
little difference. Of course, it all depends on just how much there is.
I agree with dpb without a doubt a larger tank will increase the sand
problem. I would add a filter, but still that's ofter the pump so it
won't help the pump any.
If it were mine, I'd try to run it dry. Or at least let it run 4 or 5
hours with enough faucets open so that it isn't cycling on and off.
Hopefully the outdoor spigots will take care of that. My ex father in
law worked most of his life for a water company. When ever a well isn't
producing enough, or it has dirt, they try their best to run them dry.
What happens is the tiny cracks in the rock were the water comes from
sometimes cleans itself free of the sand and sediment. It's sure to get
a bunch of sand when you do this, but once it clears up again in a day
or two, it may have less sand than now.
If sand/soil/cloudy water is a problem even when it hasn't been used for
a day or two, they normally raise the pump 10 or more feet to hopefully
keep the sediment below the pump. You could have enough sediment so it
has filled in and reached the bottom of the pump, but your well isn't
deep enough to raise the pump much so that isn't an option.
Boy, after reading this, don't ever come near my well...
You have no clue of why there's sand in OP's well, nor why it's a
problem here (and there's no hope of running this well dry w/o a pump
larger than will fit in the hole but one could surely stir up and suck
up a whale of a lot of sand and ruin it forever that way... :(
On second thought, I suppose sand spells a lot more trouble than silt
from shale or other rock. I do stand by the comments if it had been
rock, trying to run it dry. Ever see a very large stream of water
running down the road coming from a pump house of a water company? I
have many times, and I found out why.
For info: We operated two standard 3 bedroom homes (four people) for
some 15 - 20 years with shallow well pumps set at 20 and 40 lbs/
sq.inch. with no problems whatsoever. Although do seem to recall that
we did not have a dishwasher at that time.
Now (last 25 - 30 years or so) are on municipal water with somewhat
higher pressure. No problems when changing over to municipal water
using same taps/appliances etc.
That's not a bad though, actually. With that shallow a well, you could
probably raise the pump about 1 1/2 to 2 feet and get away with it, if it
didn't put it too high to suck enough water. That's likely to be enough to
get away from the silt deposits for several yeas.
Long term, it's probably going to be neccessary to have the well pumped
in a manner that will draw out the sediment; there could be a LOT Of it down
there. Depending, it's possible the well is deeper than was measured last
due to the sediment building up too.
It's not that expensive to do: And is cheaper today than it will be a few
years from now.
Newsgroups are great places to get assistance.
But always verify important information with
First off, realize that as you increase the operating pressure the
amount of useable draw-down decreases and pump cycles will be more
frequent. A larger tank will better accommodate higher operating
If you are getting sand, be sure to install a decent whole house filter
sump with a basic sediment filter cartridge to keep the sand from
clogging faucet aerators, and damaging faucet and toilet valve seats.
Since the filter normally gets installed downstream of the pressure
tank, be sure there is a drain valve installed at the tank, so you can
drain it now and then to flush out accumulated sand which reduces
useable tank volume.
There isn't much to know about the pump in the well, they're pretty
simple. Depending on the brand, quality, water quality, lightning in the
area, etc. pump life can range from around 7 years to 14 years or more.
Since your well is fairly shallow, it isn't terribly difficult to
replace the pump, I've replaced a couple on similar depth wells.
The operating pressure doesn't have a lot of effect on pump longevity,
water quality such as iron to buildup on the pump screen and sand to
abrade the impellers are more significant factors. Short cycling from
too small a pressure tank and/or too small a hysteresis will also reduce
Another note, is that if you have the space available and your existing
pressure tank is in good shape, you do not need to replace it, you can
simply add another tank in parallel. Just be sure to balance the air
charge between them so they work together.
On Tue, 16 Mar 2010 10:06:21 -0600, Pete C. wrote:
Interesting... we've got a top-side motor/pump and a submerged jet (80'
well), and the moter/pump date from the late '70s, so it's already over
30 years old (the well's newer though - 1986 IIRC - and replaced an
earlier 50' well on the property.
The only time we get any debris out of ours is if the water's shut off at
the main valve for any length of time - maybe they all do that (it's the
first house I've lived in with a private well), or maybe ours is getting
toward end of life (I believe 24 years isn't bad at all for a well, and
certainly no complaints at 30 for the pump...)
Pete C.: Thanks to you and the others for your replies. I checked
into this Lakos sand separator recommended by one of the responders,
it's very affordable at 330.00. But of course it does nothing to save
the impeller from sand abrasion. THe problem is the well guy told
me what the depth of water table is, 60 ft., and he told me what the
drawdown is: 15 ft. while pumping 15 gpm. But what I would like to
know is what total depth of well is, and what depth the pump is at.
Is there a way I drop a line with a small weight attacked and
determine these two things? It's a 4 in. well, and I am thinking if I
drop a weighted line down into it, it would just land on top of the
submersible, since there is probably not much clearance between the
pump and the well casing. I am thinking the well might be 100 ft.
It certainly has to be something more than 75 ft, as the submersible
must be below 75 ft.
I am wondering if I might raise the pump a little...or lower it, and
get into an area where it will be sucking less sand. Perhaps the pump
is at a level where the strata is just very loose sand, or there could
be corrosion holes in the screen of the well casing ringht there.
Do I need to set up an A-Frame and use that wil pulley to pull out
or change position of the pump? THe former owner of the property left
a massive A-frame of 3in pipe on property.
It is funny that no one makes a submersible with a stainless steel
impeller....for just such situations where the well is pumping sand!
At least the well guy said there isn't any such thing available.
I should add that the well water looks perfectly clear, and the water
is sweet. But if you let a cup of water stand for a few hours, you can
see some extremely fine sand particles at bottom.
Yes, I installed a quality whole house filter at the outlet from the
pressure tank. Actually replaced the old/shot one.
We had a power failure the other day, and I ran a 5 KW 115 V generator
to run the fridge and a few other things, but because the well pump is
220V, we had no way to flush the potties. I need to build some
elevated storage. I am thinking about buying some 10ft x 6 in. fence
posts set in sonotubes, to make an elevated support for a 500 gal.
plastic cistern. Hopefully the pump is still in good enough shape to
provide the needed head pressure to fill it. That way if the
electricity fails, I can open a valve below the cistern to keep the
water flowing in the house.
I have an idea to take the well off-grid, by replacing the 220V AC
pump with a 12V one which is solar-powered, and utilizing a bank of
batteries. But PV panels are still pricey, and 12V submersibles are
quite pricey, too, liike 2 or 3 times as much.
Don't know about this but I was once told if you can flush the toilet
twice and the pump doesn't come on its big enough. This is one of
those rules of thumb I picked up somewhere about 30 years ago. With
low flush toilets maybe it should be 4.
As long as the pump can keep up with whatever the max demand is, then
the only benefit to a larger tank will be less startups. Maybe you
will get longer pump life with less startups, but I haven't really
seen any actual data that shows that. Also, before moving up from a
20 something tank to a 50, I'd make sure the current one has the
proper air charge in it. You can find info on what is should be from
the manufacturer's website or use figures for a similar tank if you
can't find yours. It's possible the tank has too little air and you
can greatly decrease the cycles just by adding air.
Going from 20/40 to 30/50 pressure should be fine and within the
capability of the pump. It's actually closer to typical than the 20/40
The way I understand it the longer the pump runs when it cycles the
better, a minimum of 2 minutes. The reason is the startup heats the
pump, and it cools off as it runs. The way to accomplish this is more
storage / pressure tank capacity. As to sand, what you want is a
separator like http://www.lakos.com/products/SMP.html , that is a
little pricey, but you can find them used. They need no cartridge,
instead the silt settles out and is flushed with a purge valve
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