sand filter pressure

[Matt Lever]

hey all, hoping someone can help.
i have recently started to measure and record my sand filter PSI to know when to backwash. i have a 2 stage pump with a low and a high setting, i usually run the pump for 7 hours per day on the low setting and only use the high setting for vacuuming. looking a my pressure gauge today it reads 0 PSI on the low setting and 15 PSI on the high setting. is this a fault with the gauge? surely even the low setting should have a reading. with the pump on the low setting there is clearly water coming from the returns, so there is definitely flow and i haven't noticed the flow to be less then normal. any suggestions or help appreciated. thanks.

 

[ajw22]

Filter pressure gauge reading very low or even 0 is normal at low pump speeds. The gauge is not designed to read those low pressures.

 

[wireform]

Unless you know your system and know that at the lower speed it had a psi reading and now it doesn't, that may be a cause for concern. Things to know are, what clean filter pressure is after a good backwash since no 2 pools are alike nobody can say for sure what the pressure needs to be or is. Make sure with pump off the psi gauge returns to "0" otherwise again chance of inaccuracies. Lastly with pump in low speed you might not necessarily get a reading and it doesn't mean there's a problem either. At the higher speed is where you'll most likely make the psi determination for the routine maintenance.

 

[Jimrahbe]

Matt,

If your stock gauges are like U.S. stock gauges, it reads zero to 60.. You should replace it with a gauge that reads zero to 30... When I run my VS pump at 1200 RPM it reads about 1 to 2 lbs. With the stock gauge it reads zero...

Thanks,

Jim R.

 

[ajw22]

I use this bottom mount 0-30 PSI gauge..

Bottom-mounted Pressure Gauge

tftestkits.net

 

[Matt Lever]

thanks all for your help.
i will see how it goes over the next few months and take my reading with the pump set on high. if i get no joy i will look at getting a different gauge.

 

[cfherrman]

If you want a accurate reading (0-5 psi) you have to get a guage with a vent on it and open and close the vent monthly to equalize the pressure in the case.