Pump pressure higher this year

[mdkunkel]

We have a 2.5yo 17000 gallon in-ground pool with a sand filter (installed May 2020). The “base” pressure the last 2 summers (when clean) was around 17-18 psi. If it rose to 25 or more, I’d backwash it and the pressure would go back to 17-18. This year, the base pressure seems to be around 25. I’ve backwashed it several times with no change. Chemistry is good. Pool water level is roughly the same. Is it normal to have that much year-to-year variation?

If not, what should I look for?

Only differences this year are 1) my husband closed/opened the pool himself, and 2) there was an in-line chlorinator that we weren’t using and the connector hose kept leaking so we plugged it off.

 

[Texas Splash]

Chemistry is good.

This is where we at TFP always start. Best to post a full set of water test results from your TF-100 or Taylor K-2006C test kit. If you don't have one of those, you need one. Testing from just about any other source is questionable at best. But accurate test results would be step #1. Welcome!

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[mdkunkel]

Ive been a TF-100 kit since about 2 months after the pool was installed. (Didn’t take long to realize the algaecide and chlorine tablet combo our pool installer recommended wasn’t going to work!) Current results: pH 7.5, Cl 5, CC 0.5, TA 110, CYA 20. I’m working on getting the CYA up - we just opened the pool 2 weeks ago.

 

[Texas Splash]

we just opened the pool 2 weeks ago.

Thanks for the good test numbers. I'm considering two things: Algae or a bad pressure gauge.
We know pressure gauges can get weird fi they were left outside all winter. If yours was, check to see if it falls to zero when the system is off.

If the gauge seems fine, we go back to excessive organics still in a post-winter transition still clearing. Since we know that CYA is still in-work, I would recommend keeping the FC strong today (in the 6-8 range) and do an Overnight Chlorine Loss Test starting this evening. Let's be sure to rule-out algae. If you pass the OCLT, it would seem to point back to the gauge.

But if you fail the OCLT, it's time for a SLAM Process by doing the following:
1 - Lower pH to about 7.2 with muriatic acid
2 - Increase the FC to 10 for now since the CYA is low. If you find in the next day or so the CYA at 30, then increase the FC to 12.
3 - From there, continue with the SLAM Process.

So let us know how these options workout. If you have questions let us know.

 

[Texas Splash]

we just opened the pool 2 weeks ago.

Thanks for the good test numbers. I'm considering two things: Algae or a bad pressure gauge.
We know pressure gauges can get weird fi they were left outside all winter. If yours was, check to see if it falls to zero when the system is off.

If the gauge seems fine, we go back to excessive organics still in a post-winter transition still clearing. Since we know that CYA is still in-work, I would recommend keeping teh FC strong today and do an Overnight Chlorine Loss Test starting this evening. Let's be sure to rule-out algae. If you pass the OCLT, it would seem to point back to the gauge.

But if you fail the OCLT, it's time for a SLAM Process by doing the following:
1 - Lower pH to about 7.2 with muriatic acid
2 - Increase the FC to 10 for now since the CYA is low. If you find in the next day or so the CYA at 30, then increase the FC to 12.
3 - From there, continue with the SLAM Process.

So let us know how these options workout. If you have questions let us know.

 

[mdkunkel]

Thank you so much! That’s very helpful.

When you say “check to see if it falls to zero when the system is off,” does that mean just turn the pump off? When I turn the pump off, the gauge does not fall to zero. In fact, it doesn’t move at all, it stays at 25-26. The gauge was left out all winter so maybe that’s the problem.

 

[Texas Splash]

does that mean just turn the pump off?

Exactly. Based on your description the gauge is bad. Should be an easy fix.

 

[Texas Splash]

If you don't have any gauges locally or don't feel like running out in traffic, there are some nice glycerin filled ones on tftestkits.et.

TFTestkits.net

<meta name=google-site-verification content=AyvM6cSnKb2OYzhrqFW-2RXf8opLhr1cWK8ZCwnUVN4 />

tftestkits.net

 

[mdkunkel]

Awesome! Just ordered the new gauge from tftestkits.net. Thanks for your help!