POOLNerd vs. pool retailer - who's test is more accurate?

[P00LNerd]

Someone had asked me about my water testing routine in another thread, so posting the quick synopsis here.

The pool installer/retailer set this pool up with a Frog Leap sanitizer, and gave me the obligatory Frog test strips. We found the colors on the test strips often didn't match anything on the bottle, and were often a different color at the center of the test squares than at the perimeter of the same test squares. So, do you use the color in the middle of the square, or the perimeter? Left edge or right? They were terrible, almost totally useless.

So then we bought a Taylor 6-way test kit, which does FC, TC, pH, and Alk. This is much more useable and repeatable, but sometimes our pool retailer/installer gives us test reports that disagree with what we get from this kit. I suspect our Taylor kit may be more accurate than their system, which is based on computer optical analysis of test strips.

So then we got some better test strips, both because we wanted something that would show CYA, and just something else quick for daily checks or comparison to the Taylor kit.

Yesterday's report from pool retailer:



Free Chlorine and pH:



Total Chlorine and pH:

 

[Bperry]

Someone had asked me about my water testing routine in another thread, so posting the quick synopsis here.

The pool installer/retailer set this pool up with a Frog Leap sanitizer, and gave me the obligatory Frog test strips. We found the colors on the test strips often didn't match anything on the bottle, and were often a different color at the center of the test squares than at the perimeter of the same test squares. So, do you use the color in the middle of the square, or the perimeter? Left edge or right? They were terrible, almost totally useless.

So then we bought a Taylor 6-way test kit, which does FC, TC, pH, and Alk. This is much more useable and repeatable, but sometimes our pool retailer/installer gives us test reports that disagree with what we get from this kit. I suspect our Taylor kit may be more accurate than their system, which is based on computer optical analysis of test strips.

So then we got some better test strips, both because we wanted something that would show CYA, and just something else quick for daily checks or comparison to the Taylor kit.

Yesterday's report from pool retailer:

View attachment 582139

Free Chlorine and pH:

View attachment 582140

Total Chlorine and pH:

View attachment 582138

Your pool retailer is like lots of others, not very accurate or reliable. Try taking the same sample of water to two different stores, or same store at two different times and you might be surprised at how different they are. Its one reaosn why TFP does not trust any test results from a pool store.

Your kit is more reliable.

 

[Newdude]

You need to add a Taylor k1515 (fas/dpd) FC test to your kit. The block test is too vague to dose to our needs, only goes to 5, and tests TC which is a useless parameter.

2+3 =5 and 5+0= 5 tell two entirely different stories. The answer being '5' means nothing.

 

[P00LNerd]

Thanks, guys!

My Taylor kit does test both FC and TC separately. Basically, test FC first, then add another reagent to that mix to get TC. Not pretending it's the best kit on earth, I really don't know, but it seemed to hit all the things I was interested in testing at the time... except CYA.

6-Way Test Kit for Free Chlorine, Total Chlorine, Bromine, pH (acid demand), Alkalinity (DPD)

I had been shopping CYA-only kits last night, with a plan to add that to what I already have for now.

 

[Newdude]

I had been shopping CYA-only kits last night, with a plan to add that to what I already have for now.

The K1515 and a CYA kit will get you everything you need to be proper.

 

[P00LNerd]

The K1515 and a CYA kit will get you everything you need to be proper.

I'm not following. What's wrong with the K-1004 kit I have? Is it just that it stops above 5 ppm, or is it that you think it only tests total chlorine?

The K-1004 tests both total and free chlorine separately, but also gives Alkalinity and pH.

 

[mknauss]

What's wrong with the K-1004 kit I have? Is it just that it stops above 5 ppm, or is it that you think it only tests total chlorine?

Color matching. Easily gets bleached out if TC level is high.

FAS-DPD is accurate and fool proof.

 

[Mdragger88]

I'm not following. What's wrong with the K-1004 kit I have? Is it just that it stops above 5 ppm, or is it that you think it only tests total chlorine?

The K-1004 tests both total and free chlorine separately, but also gives Alkalinity and pH.

It’s the 5ppm limitation along with the color matching factor.
if you notice on the chart - most recommend target fc ranges are above 5ppm.
FC/CYA Levels
If your cya is actually 60 (55 counts as 60 for chlorination purposes)
you should be aiming for 7-9ppm fc.

Also, if you have an issue & need to raise to slam fc level you need to be able to accurately measure it.

As mentioned the addition of the fas/dpd test & the cya test would make your current kit complete & give you the ability to follow all the protocols tfp recommends.
The fas dpd test measures from 0.5 up to 50ppm fc & cc separately & accurately without matching colors & is not bleached out by high fc levels.

 

[P00LNerd]

Thanks, guys! Yeah, I do hate color-matching, always makes me feel half-colorblind. Which I guess I am.

The Alkalinity test I use now uses the same color-change principle as the K1515, and I'm always more confident in that.

I'll see if Taylor makes a kit that has both the K1515 contents and CYA, otherwise I'll just purchase both separately.

 

[Mdragger88]

I'll see if Taylor makes a kit that has both the K1515 contents and CYA, otherwise I'll just purchase both separately.

They do - it is the k2006/k2006c or the tf100/tfpro - this is why we recommend only those kits.
Those also contain all the other tests as well.
To get just the fas/dpd & the cya test you must purchase them separately through tftestkits.net or various retailers.

 

[AUSpool]

I often see the r0013, 9191 and 9193 as individual items on Amazon. I’ve seen the 1515 too. The speedstir or magnetic stirrer is an absolute must for self testing. You’ll probably be close to the TF100pro for the cost of the individual items.

I was going to say though that viewing the pH comparator is best with a white background. And if you’re testing outside do it in the shade and never leave the kit in full sun. And although the kit is for testing water it doesn’t like water, make sure your hands are dry after collecting a sample and store the kit inside in a cool dry spot like a laundry cupboard.

 

[P00LNerd]

All of the Taylor CYA test kits seem to make use of a cloudy water test, fill vial until dot at bottom becomes invisible. That has to be horribly inaccurate, I honestly can't even imagine it working consistently.

Are there any color-change tests available for CYA, similar to the usual red/green alkalinity test, or K1515?

 

[Newdude]

Nope. Pentair and blue devil makes a slightly different tube test for CYA. You slide a doohickie up the tube and then the doohickie points to the #. But it still uses the cloudy mixture.

It's good enough to be within 10, which is plenty close enough for what we need to do.

And you get good at it after a dozen or two tries. The problem is that CYA isn't often because it doesn't change much. So folks will go a long time before they've done it alot of times.

 

[Bperry]

That has to be horribly inaccurate, I honestly can't even imagine it working consistently.

Its fairly consistant within the range need for pool care and there really isnt a better alternative outside of lab equipment.

You really just need to know if CYA is over 30ppm and less than 90ppm. Theres not a lot of need for granularity in less than 10ppm.

 

[P00LNerd]

Thanks! I was imagining trying to keep FC at 7.5% of some unknown CYA number, but maybe it doesn't need to be as accurate as I had assumed.

Since my K1004 kit doesn't expire until the end of this season, and it seems to work fine for pH and alkalinity, I figure I'll just follow newdude's recommendation to just add K1515 and CYA separately for this season. Next year I can start with a fresh K2006, and just get it all in one kit.

The CYA kit comes in two flavors, 30-100 ppm or 0-500 ppm, the latter being double the price of the former. Which do you guys recommend? I suspect my target is always in the 30-100 ppm range, so that may be fine?

 

[Endro32]

The CYA kit comes in two flavors, 30-100 ppm or 0-500 ppm, the latter being double the price of the former. Which do you guys recommend? I suspect my target is always in the 30-100 ppm range, so that may be fine?

Yeah the 30-100ppm test is plenty and is what's included in the K-2006 kit. If you need to test CYA levels above 100, the result is the same no matter what: drain/refill. Testing that high would be pointless.

 

[CreedenceTapes]

All of the Taylor CYA test kits seem to make use of a cloudy water test, fill vial until dot at bottom becomes invisible. That has to be horribly inaccurate, I honestly can't even imagine it working consistently.

Are there any color-change tests available for CYA, similar to the usual red/green alkalinity test, or K1515?

Again, I feel you. I'd be willing to pony up pretty big for a reliable drop test for CYA accurate to +/- 1ppm. But as others have indicated, the standard turbidity test is all that's practical, and it's good enough. What you can do, however, is order a standard 50 ppm solution from TF Test Kits to see exactly what 50 ppm looks like.

 

[P00LNerd]

Looks like the kit only comes with enough reagent for 6 tests?

 

[JRzMom]

As others have mentioned, once you get your CYA up to the level you want, you don't have to test often. If the kit only has enough for 6 tests, that may be enough. Follow the recommendations for the amount of acid to add via the sock method and wait to test until it is mostly dissolved. If you buy reagent refills from tftestkits you will have plenty of reagent to get to the level you want and plenty left over for occasional testing.

 

[Endro32]

If you were to run out during the season, R-0013 is cheap on Amazon. 2oz for $10 or 16oz for $15.