Pool Store Testing with Taylor Test Kit / Reagents

[Scottc19]

My pool builder / store operates a “water chemistry lab” where they have multiple testing stations at which employees run the full suite of pool water tests “manually” using various Taylor test reagents / drop tests.

I understand the TFP community position on pool store testing, but given that they’re using the TFP-approved method/kit, does that give their results credibility? Or is the consensus here still that all pool stores are just trying to sell more chemicals?

 

[mknauss]

We trust you to do your own testing as you care what your pool water chemistry is.
Why spend the time and money to transport a sample when you can get your own kit for a nominal cost and have your data at your fingertips whenever you need it?

 

[Scottc19]

We trust you to do your own testing as you care what your pool water chemistry is.
Why spend the time and money to transport a sample when you can get your own kit for a nominal cost and have your data at your fingertips whenever you need it?

Fair point. And I do have my own kit and do test on my own. But, being new too this, have used them for validation of my own results. We are usually pretty close. Thanks for the insight and perspective.

 

[ajw22]

Stand around your pool store and see how many of the testing errors described in this article they do…

Water Testing Errors - Further Reading

www.troublefreepool.com

It usually starts with not adequately cleaning their test vials between tests. So your test sample can be contaminated by the prior tests.

 

[mgtfp]

A full range of tests takes a couple of minutes, which a pool store will not always have when there's a queue of customers waiting. There is a risk that they rush things, don't rinse properly, squeeze the bottles too hard, get distracted while talking to each other or customers and wait too long in between drops or miscount.

I would at least do a few sanity checks and verify the shop's results with your own tests. Maybe you'll work out which employees you can trust.

And make sure that they give you the actual TA, not adjusted. They can do the adjustment for themselves if they use the Taylor wheel for the CSI calculation (I don't know how accurate that wheel is by the way, I don't have one), but they shouldn't pass on the adjusted value to the customer as TA. Adjusted Alkalinity is no longer "total", it's only use is as an intermediate value for manual CSI calculation purposes. The water's buffering capabilities are determined by Total Alkalinity, which by definition includes all types of Alkalinity.

It's your pool and your decision. But when posting test results here (including published PoolMath logs), they should always be home made.

 

[Dirk]

There are many reasons why store testing is unreliable, but even if you found a store that could produce accurate results, most of the time, it still wouldn't beat your testing. What's subtle, but more important than accuracy, is consistency. Let's use CYA as an example (but this applies across the suite of Taylor tests). We advise a certain FC to CYA ratio to maintain sanitation. So you test, and then Pool Math tells you how to adjust your CYA. You dose your pool accordingly, retest CYA to confirm, and then maintain your FC, as per Pool Math, based on your CYA number. But say you notice your FC not holding as well as it should, because of a hot summer, so you up your CYA a little bit and then the FC lasts as it should. Next year, you're prepared, because you've been recording your test results, and you bring your CYA up to the level that worked the year before, and voila, you're golden for another summer.

It doesn't really matter what that initial CYA number was, or the adjusted one either. What matters is that you figured out that the CYA result you determined by your testing wasn't quite enough for your pool, and that the new value was. You were able to do that because you're testing the FC, too, and were able to notice a trend that only very consistent FC testing can reveal. And because it's you doing the testing, with whatever methods you're using to get your FC and CYA results, you were able to repeat those exact methods the next time, and dose your pool the same way, the way that works for your pool.

That's what you won't get from your store, or any store, no matter what reagents or equipment they use, or which kid does the testing. Only you will test your water the exact same way each time, even if the way you're doing it isn't exactly accurate. Five people testing CYA with Taylor reagents will get five different results. If you're one of the five, maybe your result will be off by 5ppm, or 10ppm, but it will always be off by that amount, because you're doing it the same way each time! It doesn't matter what the exact CYA number is, what matters is that you can consistently dose your pool with CYA to maintain the FC level that works for you and the way your family uses the pool.

The only way to get useful, consistent results like that, from test to test, month to month, year after year, is for you to do it yourself, the same way each time. The closer you can get to repeating the exact same methods each time, the better. And no pool store will ever be able to offer that.