Why giving advice is scary!

[larry2338]

I am 'fortunate' (?) enough to have four pool stores within 6 miles of my house. Today I took a water sample in to three of them. Here are the results:


Total Chlorine 3.0, 4.0, 5.49

pH 7.4, 7.55, 7.7

Tot. Alkalinity 98, 100, 125

CYA <40, 69, 100

Hardness levels were all similar.

I hope everyone understands that advice in this forum is given in good faith based on test results that you post.

However, if your pool store tells you, for instance, that your CYA level is 100 when in reality it is 40, it's not possible for the experts here to give you advice except that which is based on your seriously faulty readings.

If you can possibly afford it, order Ben's test kit so you'll know what's really going on with your pool. I did, and, if I understand correctly, it should have been shipped yesterday. Can't wait to get it!

[duraleigh]

Hi, Larry,

That is an excellent post.

Thanks!

[ScottS]

I agree, wonderful post.

It is scary to see that the results vary so much between 3 different stores. It's not like variances within a certain tolerance either. It could be the difference between a crystal clear pool or an algae bloomed swamp.

I would like to see one of those hidden camera news specials where they go to a few different pool stores and compare results like this.

[mas985]

I have had similar problems at the pool stores near me. In fact, one of them uses test strips and another I went to, the girl was a rookie and didn't know how to do a salt test. I can't seem to find a store that I can trust so I just rely on own testing.

[DavidD]

I would love to know:

1. What type of test they are doing (i.e. computer, strips etc.) and what brand or trade name the the test are.
2. What did your test show, assuming you have Bens/Taylor kit.

I too have questioned the validity of my local pool stores testing and have had a similar experience. That's why I don't trust anyone's test but my own!

Dave

[waterbear]

I work in a pool store that uses the LaMotte Waterlink Express colorimeter and LaMotte UDV reagents along with the LaMotte DataMate software. I have Ben's PS234s kit at home along with a Taylor K-2005, a Walmart Aquachem 6-way $15 dollar special, a few cheap OTO/pH testers, and various test strips (3 way to 6 way and some speciality ones) from LaMotte, Aquachem, and Aquacheck (Hach). There is also another pool store in my town that uses the Taylor lab for testing. I can tell you that my test results for my pool at home with all the reagent based kits that I have basically agree and also agree with the LaMotte testing done where I work, even if I am not the one testing my water at work. (Everyone where I work that does water testing has to pass the LaMotte Waterlink certification exam before they can test. The exam basically checks that your testing procedure is correct and that you are aware of any interferences that might give strange results, not very in depth but better than nothing). If there are differences between tests they are very small (for example, one test might show TA at 100 ppm and a different one at 110 ppm...certainly withing precision vaiences.

The test strips are useless! I am particularly disappointed in the LaMotte strips. I really expected better from them. The ONLY strip that I have used that proves to be reliable and accurate is the Aquacheck White test strip for salt. Evey time I have checked it has been within less than 200 ppm from a Goldline handheld salt tester that I personally check for calibration at the store weekly against the Goldline standard solution (The department manager used to do that before I started working there and he has passed the job of meter calibration on to me).

Now the other store in town is a different story. I have had test results that were spot on and ones that were so far in left field it was scary. It seemed to depend on who in the store was doing the testing. I have even asked to see the comparators on the DPD tests so I could see what they were getting when I knew the numbers were off. It all boils down to operator technique. If you want good test results get a good kit and learn to use it!

If you are lucky enough to find a pool store that understands their testing procedures and calibrates their meters if they use them you are probably OK but then again, how can you really know? Just becuase a store uses a large, impressive looking lab setup to test doesn't mean the operator knows what he/she is doing!
Bottom line is water testing is only as good as the person doing it! Just because someone works in a pool store doesn't make them an expert on water testing. I would trust most of the forum members to test my water before I would trust most pool stores. Even the newbies becasue they are getting good info on proper testing techniques and are getting a good education of what is actully happening chemically in their pools!
Just my 2 cents!