Which readings to use?

[peco]

I just recently had my pool water checked at 2 different pool stores. They are literally across the street from each other and the tests were done within 15 minutes of each other. The problem is the results are vastly different. Pool store one used a BioGuard testing system which appeared to be more automated. Pool store 2 used the typical drops, agitation and shake tests. Here are the results:

Pool Store 1 Pool Store 2

Total Chlorine 5.5 5.0
Free Chlorine 3.9 5.0
PH 7.5 8.0
Total Alkalinity 95 100
Calcium Hardness 250 360
Stabilizer (CYA) 50 100
Salt 3100 2600 (AutoPilot reads 3500)


My pool looks good but of course each pool store is trying to sell me it's own set of chemicals to correct
any issues. Which results should I use? Or would purchasing my own test kit be more accurate?
Thanks for any advice.

 

[JasonLion]

Purchasing your own test kit is by far the best solution.

These results are a little more mystifying than usual. It is difficult to get the PH test wrong by that much, yet clearly one of the stores did. If one of them made that error then there is no reason to believe their other results. But it isn't obvious which of them is wrong.

 

[frustratedpoolmom]

Your own test kit.

 

[Butterfly]

Hi peco,

Yep, your own test kit. I recommend the TF Test kit sold by duraleigh (Dave) one of our members. His kit also comes with 'customer service'! Link in my sig.

You will never regret having total control over your water chemistry!

Welcome to the forum.