Pool strips inaccurate, or something really wrong with my pool?

[vwt1572c]

Hello all
New pool owner here as of May. We have a 16000 gallon in ground. The previous owners had a pool guy who comes every other week, and we have decided to have him keep coming until get a good feeling of how to take care of it ourselves. He came yesterday and his report left a CL 2.0, PH 7.6, ALK 90. From what I can understand those are all good numbers. I went and bought some test strips today, and tested it the number 4 different times all from different locations following the directions of course. I showed a CL around 5-6, a ALK about 20-40, and PH so low it didn't even register on the lowest number of 6.2. Not that means everything, but the pools is crystal clear and blue. Are these are bad test strips, or Is something else going on? I cant see how anything could change that much in 24 hours.

Thanks!

 

[Dan Morrill]

You have found the right place to learn. Start reading through pool school on this forum. Start with these two articles that highlight basic chemistry for your pool.
ABCs of Pool Water Chemistry
FC/CYA Levels

To answer you question, yes indeed! Test strips can be extremely inaccurate. However, so can the tests performed by pool stores and pool services. Some of them just stick a test strip in the water themselves!

You need to invest in a proper test kit to get an accurate chemical reading on your pool. Cheap kits don't test for everything. You'll need one of these.
Test Kits Compared

 

[Newdude]

^^^^^^^^^. *All of that.

Welcome VDubs !!

 

[vwt1572c]

You have found the right place to learn. Start reading through pool school on this forum. Start with these two articles that highlight basic chemistry for your pool.
ABCs of Pool Water Chemistry
FC/CYA Levels

To answer you question, yes indeed! Test strips can be extremely inaccurate. However, so can the tests performed by pool stores and pool services. Some of them just stick a test strip in the water themselves!

You need to invest in a proper test kit to get an accurate chemical reading on your pool. Cheap kits don't test for everything. You'll need one of these.
Test Kits Compared

Thanks- yeah I will likely by a test kit soon. Question though- is it even possible for a pool ph to be that low (below 6.2 based on strip color) without it being obvious by sight or feel? I took a swim earlier and felt great.

 

[Newdude]

is it even possible for a pool ph to be that low (below 6.2 based on strip color) without it being obvious by sight or feel? I

Very much so. With typical pool store methods, puck and shock are heavily favored and both are staibilized with Cyanuric acid. They raise the CYA through the roof and bottom out the PH to an untestable amount.

The pool stays clear long past the point of no return and by the time the owner realizes it, they are in too deep.

 

[borjis]

Test strips = Guess strips