Float switch adjustments needed due to less water available to fill storage tank

[Shawn Parker]

My system- 56' well, foot valve @ 52', water table @ 22' normally, 2 line 220v jet pump, 1100 gallon storage tank with float switches, 2 pressure tanks, and a booster pump.

This set up has always worked without a problem, being able to refill the 300 gallon difference from pump on to pump off float switches.

My issue- due to the severe drought in Calif. the recovery rate of the water table isn't enough to refill the tank to shut off the pump. So my pump keeps running and loses its prime also. I now have to turn off the pump, wait a little, prime the line, and turn on the pump again, which will finish refilling and shut off as normal.

My question- can I raise the 'pump on' float switch so that there is only a 200 gallon volume to fill tank to 'pump off' float switch? At least until we get some substantial rain to refill the aquifer to normal capacity.

 

[Reach4]

My system- 56' well, foot valve @ 52', water table @ 22' normally, 2 line 220v jet pump, 1100 gallon storage tank with float switches, 2 pressure tanks, and a booster pump.

This set up has always worked without a problem, being able to refill the 300 gallon difference from pump on to pump off float switches.

My issue- due to the severe drought in Calif. the recovery rate of the water table isn't enough to refill the tank to shut off the pump. So my pump keeps running and loses its prime also. I now have to turn off the pump, wait a little, prime the line, and turn on the pump again, which will finish refilling and shut off as normal.

My question- can I raise the 'pump on' float switch so that there is only a 200 gallon volume to fill tank to 'pump off' float switch? At least until we get some substantial rain to refill the aquifer to normal capacity.

In your case, I suspect you should have a device that turns off the pump for a while, when the well runs out of water, would be useful in series with the float switch that shuts off the deep pump when the open air tank is full. https://cyclestopvalves.com/collections/cycle-sensor-pump-monitors is one such device.

 

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[Shawn Parker]

In your case, I suspect you should have a device that turns off the pump for a while, when the well runs out of water, would be useful in series with the float switch that shuts off the deep pump when the open air tank is full. https://cyclestopvalves.com/collections/cycle-sensor-pump-monitors is one such device.

I don't have a deep pump, I have an above ground 2 line jet pump with a foot valve down in the well. When the well runs dry the well pump also loses its prime, so turning the pump back on after the well has recovered a volume of water will not start pumping water until it is primed first.
My question remains... Should I raise my 'pump on' float switch so it turns on at a 200 gallon deficit (which the well can supply)instead of a 300 gallon deficit (which the well now cannot supply because of the drought )

 

[Reach4]

I don't have a deep pump, I have an above ground 2 line jet pump with a foot valve down in the well.

If two pipes run to the well, they are called deep well pumps. A shallow jet pump has the venturi at the pump, and a deep one has the venturi down the well.

There is a thing that is sometimes done where the venturi/ejector is set higher in the well, and a long tail pipe is but between the ejector and the foot valve. As the water level falls and approaches matching maybe 30 ft -- depending on barometric pressure-- the water flow slows to match the replenishment rate of the well. So prime is not lost, because you don't suck air. The problem is that you could end up with a tail close to the bottom and sediment could be pumped up.

I suspect you have a 2-inch well, since you don't use a submersible pump. But if you had a 4 inch well, you could go to a submersible pump. Priming is never a problem with a submersible. You can still run short of water, so you need something to shut off the pump if that is going to be happening.

 

[Bannerman]

Raising the height of the activation float in your cistern may remedy the situation as you suspect, but that will be conditional on the well's current recovery rate as to the number of gallons that may be removed at one time

While removing less water from the well will be beneficial, because you don't know how many gallons are removed before the water level is drawn down to the foot valve, the well may continue to run out before even 200 gallons is removed. Perhaps it will support only 100 gallons removal at one time?

 

[VAWellDriller]

Raising the float would work just fine, or you could also restrict the output of the pump so that it more closely matches the well capacity.

 

[Reach4]

My question- can I raise the 'pump on' float switch so that there is only a 200 gallon volume to fill tank to 'pump off' float switch? At least until we get some substantial rain to refill the aquifer to normal capacity.

If you have the type of float switch with a tether, and you want to make the float switch turn on more frequently, but for less time, shorten the tether. So you would both shorten the tether and raise the attachment point.

I still think a more sophisticated system may be needed.

 

[Shawn Parker]

Raising the float would work just fine, or you could also restrict the output of the pump so that it more closely matches the well capacity.

Thank you... that's basically all I wanted to know. This is all because of the severe drought in Calif, in combination with it being late Summer, resulting in the problem in question, which just started recently and should remedy itself when the rains start and recovery volume increases.
This 'fix' will only be needed until then.

 

[Shawn Parker]

If you have the type of float switch with a tether, and you want to make the float switch turn on more frequently, but for less time, shorten the tether. So you would both shorten the tether and raise the attachment point.

I still think a more sophisticated system may be needed.

the system has been fine for 40 years as is. This is all because of the severe drought in Calif, in combination with it being late Summer, resulting in the problem in question, which just started recently and should remedy itself when the rains start and recovery volume increases.

 

[Shawn Parker]

Raising the height of the activation float in your cistern may remedy the situation as you suspect, but that will be conditional on the well's current recovery rate as to the number of gallons that may be removed at one time

While removing less water from the well will be beneficial, because you don't know how many gallons are removed before the water level is drawn down to the foot valve, the well may continue to run out before even 200 gallons is removed. Perhaps it will support only 100 gallons removal at one time?

This is all because of the severe drought in Calif, in combination with it being late Summer, resulting in the problem in question, which just started recently and should remedy itself when the rains start and recovery volume increases. From what I've observed there isn't 300 gallons available which is the set amount between pump on and pump off. When it runs dry and I turn pump off and wait 30 minutes then turn it back on, it only runs for bout 20 minutes before it's full and shutting off.
So I'm thinking that I'm getting over half of 300 gallons before running dry.

 

[Shawn Parker]

If two pipes run to the well, they are called deep well pumps. A shallow jet pump has the venturi at the pump, and a deep one has the venturi down the well.

There is a thing that is sometimes done where the venturi/ejector is set higher in the well, and a long tail pipe is but between the ejector and the foot valve. As the water level falls and approaches matching maybe 30 ft -- depending on barometric pressure-- the water flow slows to match the replenishment rate of the well. So prime is not lost, because you don't suck air. The problem is that you could end up with a tail close to the bottom and sediment could be pumped up.

I suspect you have a 2-inch well, since you don't use a submersible pump. But if you had a 4 inch well, you could go to a submersible pump. Priming is never a problem with a submersible. You can still run short of water, so you need something to shut off the pump if that is going to be happening.

I have an 8 inch well, the ejector and foot valve are together at 52' in a 56' well, with the water table being somewhere around 22' in 2018, but must be lower with slower recovery because of the drought and it being late Summer.
It must suck air because it stops pumping water when there is none available and the pump still runs. After turning it off and giving some time to recover, it must be primed for the venturi effect to work. Then it will continue filling the rest of the 300 gallon volume needed to turn off the pump. Which will turn on again after 300 gallons is used, but unable to supply 300 gallons to reach the level to turn off the pump. Then the cycle continues as above. That's why I'm asking my question about raising my 'pump on' float switch, which really is just changing the amount of water needed to turn the pump off to an amount the well can supply right now in the current date, until the rains come to bring up recovery rates and water table, and I can reset it to normal hopefully.
This system was installed in 1964, storage tank and booster pump added in the 80s. Not sure when the submersible pump was available for use, but I doubt it would have been preferred in this particular situation because of the water itself. The water quality was tested, and it said specifically that it is "sweet water, having no odor or taste... but it WILL eat fixtures". A softener was recommended, but that would do nothing to save a submersible pump from the corrosive effects of the water. So it was never really a practical option to take.

 

[Reach4]

Which will turn on again after 300 gallons is used, but unable to supply 300 gallons to reach the level to turn off the pump. Then the cycle continues as above. That's why I'm asking my question about raising my 'pump on' float switch, which really is just changing the amount of water needed to turn the pump off to an amount the well can supply right now in the current date, until the rains come to bring up recovery rates and water table, and I can reset it to normal hopefully.

That may work, but if you simply move the tether point up, the float switch may not turn off the pump when the tank is full. You would want to shorten the tether too. Does that make sense? Did my post in #7 lead you to believe that I did not understand your objective, or was my interpretation of your objective mistaken?

While float switches with tethers are most popular, there are other types of float switch.

This system was installed in 1964, storage tank and booster pump added in the 80s. Not sure when the submersible pump was available for use, but I doubt it would have been preferred in this particular situation because of the water itself. The water quality was tested, and it said specifically that it is "sweet water, having no odor or taste... but it WILL eat fixtures".

Use of multi-stage centrifugal submersible pumps in wells started in the 1950s. Some people are early adopters, and some are not. One thing that was not available in the 1960s were electronic devices that can monitor the pump current and detect that the water has dropped closer to the intake, and shut down the pump for a while.

https://www.thedriller.com/articles/86889-how-to-use-tail-pipe-on-deep-well-jet-pumps discusses another way to prevent a deep jet pump from sucking air, but you don't have much depth to play with to implement that. Your foot valve is pretty close to the bottom.

Regarding "eat fixtures", that sounds like low (acid) pH. It is pretty easy to measure pH. I don't know how much more acid/corrosion resistant deep well jet pumps are vs submersible, but that would seem to favor the jet pump.

 

[Valveman]

As was said, shortening the tether to produce fewer gallons per cycle and restricting the flow to make it take longer to fill are both ways to solve that problem.

 

[LLigetfa]

The elephant in the room nobody is talking about is overall consumption. There is no magic float setting that will make the well keep up with demand. If you are drawing water while the tank is refilling, you will be drawing that much more water from the well. You might be better off slowing down the refill rate to more closely match the well recovery rate. There are a few ways to do that. One way is to reduce the flow with a dole valve. Another way is to raise the injector and add a longer tailpiece to shift the pump curve.

 

[Shawn Parker]

Raising the float would work just fine, or you could also restrict the output of the pump so that it more closely matches the well capacity.

How would I restrict the output of the pump? Is it a fairly simple procedure?

 

[Valveman]

You just need a ball valve. However, you do not need to restrict the pump as long as the pump can run for at least 3-5 minutes before the well is dry. Running for less than a minute or two is bad for the pump. Using a Cycle Sensor the pump will be shut off 10 seconds after the well is dry, and the timer in the Cycle Sensor lets you set the pump restart time from 1 minute to 5 hours. If you have enough water you can restrict the flow and make the pump run times longer. But you will get more water letting it pump as much as it can for as long as it can, then only letting the well recover for 10-20 minutes before restarting the pump.