Digital Photometric vs Test Strips

PSRosie

New member
Sep 15, 2020
2
Palm Springs, California
Built my saltwater pool three years ago and left care and maintenance to others. Now that I have fired my fifth pool guy (he replaced my Intellichlor SWG backwards),
and inspired by the pioneers who won the West, I am now my own pool lady.
Fully committed to the “garbage in, garbage out” theory, I am skeptical of the accuracy I can obtain with test strip color comparison. I expect there’s a good deal of art and experience vs. science involved in using strips to determine how much or how little salt to put in the stew. A digital readout, photometric device like the Lamotte ColorQ 7 really appeals to me as a potentially highly accurate and scientific way to make those expensive decisions. Thoughts? Advice? Thanks!
 

Chasarms

Silver Supporter
May 8, 2020
347
Dardenne Prairie, MO
The accuracy of the ColorQ has been rightfully questioned. I have one that my wife won at a "pool school" after I bought the Taylor.

Personally, I have found the two kits to test reasonably closely, but I have only done tests with the Lamotte a few times. While I appreciate the novelty of it, it is a real pain in the backside to use as compared to the Taylor, IMO. It takes too long to properly clean up and store.

The upsides are obvious. It gives you a number, but it has downsides:

  • It is only a 5 ml water sample. So it's easy to be off.
  • The test tubes are tiny, so it is a big time pain to clean and dry them.
  • Some of the test chemicals have a very short shelf life
  • Crushing the tablets for the CYA test is tedious
  • BIG ONE: you can't test FC over 10 ppm
  • BIGGER ONE: Accuracy. Too many people have had negative experiences with accuracy for me to trust it. Yes, I have not experienced that, but the one I have has only been used maybe 5-6 times. Most of the information at this site seems to suggests it becomes a bigger issue over time. This could be due to the aging of the test chemicals. the cleanliness of the test unit or simply the life span of the unit itself. In any case, it seems to be an issue.

And finally, the most import reason I would not use it is this site. There is a wealth of knowledge and wisdom on this site that you just can't tap into anywhere else. Since finding this site and adopting its principles, my pool has been without issue. It was a complete joy all summer, thanks to TFP. But, in the event that I do need support, I know that the gurus here are not going to be able to offer sound advice if they cannot trust the information that I give them. I fully understand and appreciate their point of view. I use the testing methods supported by this online community because I will one day have to ask them to support me.
 
Last edited:

HermanTX

Gold Supporter
May 20, 2020
772
Katy TX
The accuracy of the ColorQ has been rightfully questioned. I have one that my wife won at a "pool school" after I bought the Taylor.

Personally, I have found the two kits to test reasonably closely, but I have only done tests with the Lamotte a few times. While I appreciate the novelty of it, it is a real pain in the backside to use as compared to the Taylor, IMO. It takes too long to properly clean up and store.

The upsides are obvious. It gives you a number, but it has downsides:

  • It is only a 5 ml water sample. So it's easy to be off.
  • The test tubes are tiny, so it is a big time pain to clean and dry them.
  • Some of the test chemicals have a very short shelf life
  • Crushing the tablets for the CYA test is tedious
  • BIG ONE: you can't test FC over 10 ppm
  • BIGGER ONE: Accuracy. Too many people have had negative experiences with accuracy for me to trust it. Yes, I have not experienced that, but the one I have has only been used maybe 5-6 times. Most of the information at this site seems to suggest it becomes a bigger issue over time. This could be due to the aging of the test chemicals. the cleanliness of the test unit or simply the life span of the unit itself. In any case, it seems to be an issue.

And finally, the most import reason I would not use it is this site. There is a wealth of knowledge and wisdom on this site that you just can't tap into anywhere else. Since finding this site and adopting its principles, my pool has been without issue. It was a complete joy all summer, thanks to TFP. But, in the event that I do need support, I know that the gurus here are not going to be able to offer sound advice if they cannot trust the information that I give them. I fully understand and appreciate their point of view. I use the testing methods supported by this online community because I will one day have to ask them to support me.
Well said!!
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,143
Central California
Hi Rosie! Welcome to TFP. We're so glad you found us, and especially glad to hear about your theory of pool care: “garbage in, garbage out.” You couldn't be more right, and your instincts about test strips are dead on. Give TFP a real shot, and you'll be very happy with the results. We don't endorse any testing methods other than using either of only two recommend test kits. @Chasarms' post was excellent and his real-world experiences are typical.

Have a read through this article, do what you can of the instructions, and follow the links in it to other articles about the test kits we recommend. Grab one of the kits, and post some test results here in the forum and the experts here will analyze them and offer any needed advice.


You're not going to believe the level of support this site provides. It really is an amazing community. And now you're a part of it! And this site offers a full range of pool and pool-related advice: from scientists and pool builders and all sorts of experts. I think there's even one or two of us that knows which way an SWG is supposed to go! ;)
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
14,815
Evans, Georgia
A fancy dancy automatic device is only as good as its "eye" and calibration. I personally have little use for them.

The TF-100 is a test kit a mom & pop business started based on the TFP method. Each test is based on drops of reagents (Taylor Reagents) which you count as the color of the test sample changes. It is a very obvious change (like pink to clear or green to pink), not a color matching change. www.tftestkits.net

The only other test kit we actively endorse is the Taylor K-2006C. But that costs far more than the TF-100, but they both are about equivalent in the quantity of reagents provided. Found on Amazon, etc. Be careful to obtain fresh reagents and the correct stock number (2006, NOT 2005..)

The test kit is the basis for all we do here. It lets us all speak the same testing language.

Maddie
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
11,039
Franklin, NC
Please do not confuse the specificity of the results the ColorQ gives with accuracy. We have had members attempt to use the ColorQ to follow our methods and almost all have abandoned its use due to inaccuracies and inconsistencies. We even had one member test the same sample of water three times in a row and ended up with three different sets of results. Here is an example of a ColorQ post:

ColorQ vs TF100


Please do not read this to say that we are "down" on the ColorQ. To quote Dave, Site Owner of TFP:
Throughout TFP, you will read that we suggest certain levels that good science and practical experience has taught us fall within safe ranges.

Further reading of posts here will draw you to the inescapable conclusion that these guidelines work.......in thousands and thousands of pools worldwide.

You may or may not choose to use these methods and guidelines or you may use some and not others. Our goal is to teach you what has been proven time and time again and then let you use that information to your benefit.
We have found that drop based testing using Taylor reagents provides accurate and repeatable test results. These are what we need to make reasonable recommendations for pool chemical additions.

Should you choose to get one, I would recommend comparing your results to the "gold standard" testing at least a few times during the pool season. You could use a TF-100 Test Kit ™. Then, continue to test with your ColorQ and prove us wrong. Keep a log and let us know how it's going. You could be the one to make us feel comfortable about the device.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,930
San Dimas, CA (LA County)
These older threads may be of interest