Increasing the PSI: am I being too cautious?

[Tubby]

In researching solutions for my residential spring-fed, submersible pump system (which I detailed here), I notice an almost universal recommendation to increase the water pressure. Having a current pressure range of 30-50psi, I certainly would be happy with 40-60psi (and even happier with the addition of a CSV). But I am reluctant to make the increase without fully understanding the implications.

I ask myself What reasons did the original owners (or later technicians) have for choosing 30-50? I cannot simply assume their choice was arbitrary (though it might have been). There is some evidence that the spring house has been in use for perhaps 100 years, so the characteristics of the spring would have been well understood by 1985, when my house was built and the current line was installed.

Thus, my first hypothesis is that the spring does not replenish itself fast enough to support higher pressures. I know that, by leaving an outdoor spigot wide open for some number of hours, it's possible to deplete the water level to the point where the pump is sucking air. The spring basin is only about 17 inches deep, and the pump is about 4 inches from the bottom (see photo). Could this be the reason for the current pressure settings?

Would increasing the pressure by 10psi make enough difference to risk running dry during above-average water use?

The only other reason I can think of for keeping the pressure down might have been to reduce the amount of water going into the septic tank. Again, would an extra 10psi make much of a difference?

 

[LLigetfa]

First off, you should have a flow inducer sleeve on that pump, mostly for cooling but also to reduce a whirlpool sucking air. With the sleeve, you could also set the pump a little deeper.

Pressure switches come in a variety of presets to match different situations. For example, some pumps could struggle to reach a higher cut-out and so risk dead-heading.

How much more water gets drawn is mostly a lifestyle factor but also based on friction loss which depends on your plumbing. I doubt anyone here could accurately calculate how much more water would get drawn with a 10 PSI increase.

 

[Sponsor]

 

[Reach4]

I think the higher pressure could be of use for houses with the pressure switch in the basement and have a second story. Also, if you are watering your lawn, your sprinklers may work better with more pressure.

I adjusted my pressure from 30/50 to 38/58. I did not notice much difference. I chose that instead of 40/60 because I got a good deal on a 60 psi pressure gauge. But I could have left it at 30/50 also.

Lower pressure is a little easier on your washing machine hoses, and bidet attachment. Lower pressure is better if you have a water hammer problem (I don't).

Newer showerheads have a flow regulator, although they still pass water at a little higher rate with higher pressure.

I expect that higher pressure will fill the dishwasher and washing machine a little faster.

 

[Valveman]

The pump itself will pump less water at higher pressure. But the fixtures will let out more water at higher pressure. Leaving an outdoor spigot wide open cause the pressure to be low and the pump to produce more water. Although, leaving a spigot only partially open can cause the pump to cycle on and off, unless you have a Cycle Stop Valve. Then you can adjust the spigot to not pump the spring dry, and the pump will not cycle in the process.

30/50 is probably because the house has been there for 100 years and that is the way we did it back then. Most houses use a 40/60 setting these days, and 50/70 or higher is not uncommon for multi-story houses and such.

Some people do not notice a difference in pressure because they have restrictions like water saver shower heads. But even if you have small pipes you can turn up the pressure until you no longer need soap in the shower. Lol! With stronger showers it will fill the septic tank quicker. But with stronger showers you can get the dirt and soap off quicker and take shorter showers.

That pump looks like it has enough stages to give you as much pressure as you want. But you do need a flow inducer and a CSV would be helpful also.View attachment 98015