Constant Pressure or Standard Submersible?

[mlblevins]

Hello all - this is my first post here, as I've never had a great deal of interest in wells, pumps, etc. But now I've got "well issues", so it's my new favorite topic!

Anyway, I live in Maryland and have a well that produces about 4.25 GPM. I've got an 8-year-old 1/2 HP Jacuzzi jet pump and a 20 Gallon pressure/holding tank. I've owned this house for about 10 months and the water has always been VERY clear, odorless and tastes fines. I've also always had at least decent water pressure as well. Recently, however, I've had issues with water pressure and sediment in the water (a LOT of sediment). I had the sensor switch replaced, but the jet pump is moving pressure up to about 45 psi once it switches on and runs and then immediately dropping to about 25 psi when it switches off (just a few psi above the "switch on" setting). The thing is also running much longer than normal, leading me to believe it's "overpumping" and stirring up the sediment.

Anyway, I've been told that there is a worn valve that's allowing pressure to escape, as it were, and that replacing the pump and plumbing is better than simply fixing the valve. I'm fine with that, because I've heard that submersible pumps are generally preferred and I'd like to upgrade from the 20 Gallon Amtrol tank (WX-202) to the 44 Gallon (WX-250).

Finally - my question...would it be recommended to simply go with a constant pressure submersible pump, or is the standard submersible/pressure tank suitable? If the constant pressure, what would the recommended HP be? I've seen 1 HP recommended, but might that be overkill for a 4.25 GPM well?

For more background - I live in a house with 3 bathrooms and also have a dishwasher. 2 people live in the house.

Any advice, answers, musings, etc. are quite welcome!

Thanks in advance,
Matt

[Bob NH]

First, help us understand what you have.

You mention a jet pump. Do you have a shallow well jet pump (one pipe to the well) or a deep well jet pump (two pipes to the well)?

What is the diameter of the casing of your well? Is it a drilled well (3' to 6" casing) or a dug well ( 2 to 3 ft casing)?

How deep is it to water in your well?

Do you have any idea how much water the well can produce (Not the size of the pump now)?

Is cost a significant consideration?

Are you planning to do it yourself or hire someone?

I would not go with the constant pressure sustem with a 4.5 GPM pump. It is barely going to make the flow you need, so you need a storage tank.

A 1 HP pump seems large for 4.5 GPM. If you get a submersible you will probably be able to use a pump with less horsepower than a jet.

The loss of pressure could be a leaking foot valve, which is a check valve at the bottom of the pipe going into the well. It is possible that you could work around that by installing a check valve at the inlet of the pump, though there are reasons not to do that.

[Bob NH]

When I was referring to a storage tank, I was thinking about the 44 gallon tank that you are considering.

You can use a pressure tank for storage by setting the precharge pressure farther below your start point.

For example, assume that you want to operate between 40 and 60 psi.

You could precharge the tank to 20 psi.

At 40 psi the tank will contain 16 gallons of water. At 60 psig it will contain 23.5 gallons, so the available drawdown is 7.5 gallons which is plenty for your 4.5 GPM pump.

But if you have a larger demand than the 4.5 gpm pump can supply, you have a reserve of 16 gallons before you are limited to the 4.5 GPM pump capacity. You can get a little more reserve if you operate between 45 and 60 psi.

If I were replacing the pump, I would consider a little larger capacity submersible if the casing is big enough. For example, the 1/2 HP Goulds 5GS05 will deliver about 6.8 GPM at more than 60 psi from a well at a depth that could be served by a shallow well jet pump.

[mlblevins]

Unfortunately, there are some details of the well that I'm not familiar with - I don't know the well depth or whether it's drilled or dug. I do know that my jet pump is a deep well pump (2 wires) and that it's 1/2 HP. We are, for the sake of moving forward, going to dig it up and find out, but are working from the assumption that it's at least 100 feet and is drilled and, further, that it is 4" or more. We'll adjust as necessary after finding these things out.

The guys I'm getting to do this work (I'm not doing it myself) are going to install a 1/2 HP Goulds 5GS05 as Bob NH has suggested - they suggested this exact pump and also let me know that the WX-250 (44 gal. tank) would be good.

Other info - Initial GPM during the yield test was actually 6.6 GPM right away, then 5.45 after 15 minutes and fell to a fairly constant 4.28 shortly after that.

Anyway, I wasn't second guessing the guys who are doing the work...they seem quite knowledgeable. However, they did mention that a constant pressure pump was an option, albeit more expensive. I told them I'd think about it, but wanted other input besides theirs on this issue.

From what we know thus far, does the Goulds 1/2 HP 5GS05 and WX-250 seem like a good option? Though I'm sure it would work quite well, it doesn't seem to me that a booster pump/storage tank/pressure tank setup is necessary...keep in mind that I was entirely satisfied with water quality and pressure with the jet pump and 20 gallon tank setup (until recently when things broke down) and now I'm just replacing it with a presumably better pump and larger tank.

I guess I have another question or two on top of that - I currently have no filtration in place, other than on my refrigerator water/ice dispenser. Wondering if anyone recommends a spin-down filtration system to keep sediment out of the water?

Additionally, potability tests showed good water, and the only other issue I may have with the water is that it could be slightly acidic. So if the spin-down would be a good option, is there some addition/attachment to the spin-down that also takes care of pH levels?

Thanks again!
Matt

[Bob NH]

If you have solids in well water, you often have a range of solids. A spin-down will remove coarse sand. It will not remove finer material. I would not install one.

The reduced flow was probably caused by the lowering of the water in the well. That reduces the capability of the jet pump. What you need to determine is the level of water before and during pumping.

The 5GS05 should give you 5 GPM to 60 psi with water level down to 100 feet below the surface. It will probably do more than that. Whatever the water level, it should do better than the deep well jet for the same conditions.

You should be sure that the well is pumped until the water clear with a work pump (not your new pump) down near the bottom of the hole. If there is sand and sediment in the well, you want it cleared out so it doesn't damage your new pump.

[mlblevins]

Bob NH - thanks again for your reply. I'll make sure the guys that are doing the work do just that, i.e. - pump the well with a work pump until the water is demonstrably clear.

Again, thanks for helping out a newbie on the subject. I'll let y'all know how things go!

~Matt