testing with strips

duraleigh

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In The Industry
Apr 1, 2007
32,863
Sebring, Florida
4jaw,

Regardless of the outcome of the test strip results, there is simply too much evidence over the years to do anything but conclude that test strips are inadequate for the precision we talk about here on this forum.

Of course, I have a dog in the the fight but long, long before TFTestkits existed, it was apparent to me that test strips were inadequate to effectively manage your pool. There are simply too many posts on this and other forums that demonstrate the inadequacy of strips.
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
duraleigh said:
4jaw,

Regardless of the outcome of the test strip results, there is simply too much evidence over the years to do anything but conclude that test strips are inadequate for the precision we talk about here on this forum.

Of course, I have a dog in the the fight but long, long before TFTestkits existed, it was apparent to me that test strips were inadequate to effectively manage your pool. There are simply too many posts on this and other forums that demonstrate the inadequacy of strips.
Well that really is the question isn't it...precision.

At what precision do I need to measure things like FC and PH?

For my pool with a CYA level of 55 anything between 5 and 10 for FC is close enough because tomorrow it will be two points below that.

For PH all I need to know is if its between 7.4 to 7.6 for me to be happy.

From my experience knowing the volume of the pool was far more important to proper dosing than what I seen in the drop tests, I needed to know what the levels were for sure...but what counted was how much to add to correct to achieve the proper result.

Do I care if my FC is 6 or 7? No, its within safe range for my pool...and tomorrow I will add the appropriate amount to account for normal daily loss. If I let the FC drop to 5 am I going to freak out? Of course not, I will add some after we are finished swimming for the day and correct it to midrange of 7 at the end of the day...or if I am lazy I will raise it to 10 so by the end of tomorrow it will be 8.

I have options.

Strips are an option thats all I am saying, they aren't the holy grail but they aren't the bogeyman either if you know what you are doing.

BTW I just tried five of the strips completely unscientifically and the results matched my DPD drop test exactly...PH, FC, TA were all what I would expect them to be and these strips confirmed what I already knew. I am still not satisfied with this test kit because the FC range only tells you if its between 5 and 10, I would prefer a two part strip that tells me the FC level more closely...I could care less what my TA is since I only correct it twice a year and it hardly moves. The PH color on the strip was bang on match for my DPD drop test, I tried 5 strips and layed them side by side and they all agreed with each other. PH was 7.5...and thats all I needed to know. At 5 cents a strip, thats cheap knowledge I can now trust.

So how is this bad? Am I able to superchlorinate using a strip (I never have to do that anyway). No!

Am I able to check my CYA with this strip? Who cares it hardly moves over three months.

Is my TA within the range of 80-120? Yep, my DPD drop kit tells me its 100 exactly but who cares if it only needs correcting twice a year.

Using an "indicator strip" requires knowledge of the scope and purpose of the device which is where 99% of the users of the strips are failing in my opinion, in this case it is a verification tool that takes less than 5 seconds to administer and read. An indicator strip failure requires intervention and this is where my DPD test kit comes in, in medicine thats when they call me to find out whats wrong and repair or adjust to find out the problem.

I just think making blanket statements that strips are useless or give false readings without scientific first hand proof is misleading, I see a purpose and use for them in my pool maintenance regimen and will continue to look for the perfect one that fits my needs.
 

teapot

In The Industry
Jul 25, 2009
574
London and France
4JawChuck said:
BTW I just tried five of the strips completely unscientifically and the results matched my DPD drop test exactly...PH, FC, TA were all what I would expect them to be and these strips confirmed what I already knew. I am still not satisfied with this test kit because the FC range only tells you if its between 5 and 10, I would prefer a two part strip that tells me the FC level more closely...I could care less what my TA is since I only correct it twice a year and it hardly moves. The PH color on the strip was bang on match for my DPD drop test, I tried 5 strips and layed them side by side and they all agreed with each other. PH was 7.5...and thats all I needed to know. At 5 cents a strip, thats cheap knowledge I can now trust.

5 strips from the same manufacturer of from different? As the strips are not graduated in the same steps as FAS DPD I doubt the strips matched exactly, only within a range and that is the point if you require accuracy to sort out a problem. I know lots of people using strips and when all is fine I don't hear from them. When something goes wrong my phone never stops.

Using an "indicator strip" requires knowledge of the scope and purpose of the device which is where 99% of the users of the strips are failing in my opinion, in this case it is a verification tool that takes less than 5 seconds to administer and read. An indicator strip failure requires intervention and this is where my DPD test kit comes in, in medicine thats when they call me to find out whats wrong and repair or adjust to find out the problem.

I just think making blanket statements that strips are useless or give false readings without scientific first hand proof is misleading, I see a purpose and use for them in my pool maintenance regimen and will continue to look for the perfect one that fits my needs.
There seems to be plenty of first hand proof that strips are not wonderfully accurate however as a quick test to see if there is chlorine in the pool and the PH level (the two most common tests) they do work as an indicator. I was talking to Palintest the other week and they said even their strips were only a rough indicator. A few years ago all we were using was phenol red PH and OTO so we have come a long way and pool stores could get customers buying all sorts of magic potions, That balance of power has now shifted/shifting so it's all good unless you are a pool store.
 

Undrwtr1

LifeTime Supporter
May 16, 2011
29
OK. Not to stir up a hornet's nest, but I see that everyone generally agrees that the Taylor Kits and Reagents are the most accurate and most recommended. I also notice that Taylor makes strips http://www.taylortechnologies.com/produ ... KitID=2555 - has anyone tried their strips to compare the accuracy to the Aquachek series or others? I am a recent convert to BBB and full test kit, which has become very easy in the past 2 weeks of testing, but I still recall with fondness throwing a few pucks in the chlorinator and dipping a strip each morning - 2 minutes versus 10. Just curious if the Taylor strips have any greater accuracy or precision compared to the others.

Thanks!!

Gerry
 

RobbieH

TFP Expert
LifeTime Supporter
Aug 30, 2010
4,052
Dallas, TX
Underwater,
I also was looking for something that required less maintenance, so I installed a Liquidator and added borates to the pool. The LQ has been installed for 3 weeks, the borates have been in for 6 days. My chlorine levels are so stable I just run out and do a quick DPD test for chlorine daily (I'm still learning the new nature of the pool) and the FAS test once every 3 days until I know things are stable, then will go to once a week. I have some pucks floating right now to increase CYA, once the FC starts dropping I'm going to open the valve on the LQ again. I feel once I have a feel for how the pool reacts as time goes on, I won't need the FAS test again unless for some reason I need to shock, or if I just want to check with a more precise test than the DPD. Since I like knowing exactly what is going on with the pool, I'll probaby do the FAS once a week from now on.

The reason I bring all this up is there are ways to make your pool easier to maintain. If not a Liquidator, maybe one of the chlorine auto feeders, or go to SWG.
 

madwil

Well-known member
May 2, 2011
370
lebanon tn
Canuck, I have yet to see anyone here blast strips, other than when trying to define parameters for SHOCKING a pool. I have even read here of others who use the test strips as PART of their pool maintenance, followed by the more definitive testing with a complete and accurate test kit.
I myself use OTO test daily, with a complete test about once a week...
So, yes, the opinion here is the TF100 or Taylor 2006 is a better test kit, and essential for maintaining a pool IAW the directions found here. It is not the only way to test, and not the only way to maintain a pool; it's just what everyone here has found to be the best way for us.
Chemgeek does get windy sometime, but if you'd take the time to read his posts occasionally, you might learn something that will help you later, or help you helping others later! PS, your preceding msg was 4 paragraphs, chemgeeks was 5 with a cut/paste chart for those interested in the comparison- not significantly more lengthy!

With regard to medical test strips, you are comparing apples and oranges; the QC in medical tests are significantly higher, with a corresponding increase in price. If you paid to the poolstore what you paid to the Doctors office/hospital, they'd get more exacting dipsticks also... besides, in most cases (especially for sterility) it is a generic go/no go test, not a precise measure of amount; it's either sterile or it ain't!
 

JasonLion

TFP Expert
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May 7, 2007
37,879
Silver Spring, MD
The problems with test strips are inherent. There is no easy way to control the exact amount of pool water that reacts with the test pad, so there is an inherent lack of precision. Some brands also have problems that make them even worse than that, but a couple of brands have already approached very close to the best you can do. I haven't tried the Taylor strips, but I assume they are about the same quality as some of the other top brands.