Test kit subjectivity

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JeremyNMex

0
Sep 22, 2013
6
Ojo Caliente Mineral Springs, NM
I'm red/green colorblind so can't use color comparators. I run a commercial pool, and when I started we had a Taylor K-2005C service kit. I relied on my three non-vision-impaired workers to check the results. They frequently came up with FC higher than TC, and their results differed among themselves. So I gave up and bought a LaMotte ColorQ. (I chose that one because we have an open account with In The Swim and that's what they carry.)

TFP questions its accuracy--why, and how bad do you think it is?

I was an instrument tech for 30 yrs, and my whole career centered on the question, "Is this instrument or test telling me the truth?" I can find no accuracy specs for any of the testers, and am forced to say "It's probably close enough." The wobbly repeatability of the ColorQ tells me that the 0.01 ppm resolution of its Cl/Br test is probably not justified and gives a false sense of accuracy. But I don't have a fancy lab anymore and can't be sure.

I'd appreciate comments from those of you with more pool testing experience/expertise. Thanks.
 
TFP questions its accuracy--why, and how bad do you think it is?
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Reports from many owners of the color-Q give it mixed reviews.

Of course the precision it reports is completely bogus......no big deal in that you need nowhere that precision anyway but it seems to be consistently less accurate than the drops based testing we suggest.

Several forum members actually have both types so perhaps they will chime in with their experiences.
 
Like Richard said, get a FAS-DPD test as included in the K-2006 for FC and CC, no color matching required like with the DPD test of the K-2005, all you need to be able to tell is pink or clear, however you perceive the color pink. You can by the stand alone kit from TF testkits, see link in my sig

Ike
 
I have had a Lamotte ColorQ Pro 9 Plus and a TF100 for 3 years. I test with the TF-100 weekly and the ColorQ every few weeks. Here are some of differences I have noticed.

FC - ColorQ always has a much lower value
(ex. 5.0 on TF100 and 1.13 on ColorQ. I know what FC was yesterday plus chlorine added never adds up to the ColorQ low numbers.)
CC - ColorQ does not test for this
TC - ColorQ is always the same as FC, always.
PH - ColorQ is good here, usually the same as I got with the TF100.
TA - ColorQ is about 30 lower that TF100. Why do I think the TF100 is correct? With a copper problem we do a 1/4 drain once or twice a year. I test using both test kits, drain, test again + add baking soda. The TF100 number in the end is where I should be, the Lamotte numbers are all over the place.
CH - ColorQ much lower again. (ex TF100 tests 200, ColorQ tests 55 - always a huge difference on this one)
CYA - ColorQ lower here as well and this one is never consistent. It could read 55 one week and 32 four days later where no water is lost or added. (ex TF100 80, ColorQ 55)
COP - Copper, The reason I purchased the ColorQ was testing copper and I thought the TF100 would be too difficult to arrive at proper results, especially the CYA. Copper is always at least .3 sometimes .7. I tested bottled water one day, it tested .3

The TF100 readings are accurate. I have 3 years of testing logs with both test kits that I am referring back to. I always know my current water results and when I factor in the chemicals added or the water I have added/lost, I can always get my pool balanced with the TF100.

At this point I still test with my ColorQ because I have it. I replace reagents every year as obviously I like to test. My pool is salt but with the massive rains we have had this year I went to clorox during the spring/summer. We had 15" of rain on July 27th and 8" the next day, the entire pool season was rainy.

Since I have never had a green or cloudy pool, I will assume my TF100 is giving me good numbers. I wanted the ColorQ to work because it is easy. I easily schooled myself on CYA readings on this forum. The only accurate number I feel I am getting from my ColorQ is my PH reading. With the ColorQ 9 costing close to $200, I have basically paid $200 for reading PH tests.
 
Wow, what terrific info/advice. Don't know why the FAS-DPD didn't register in my brain but it sounds like the way to go. With my pool not being a typical closed loop (hot springs flow-through at about 15gpm), TC and FC are the only variables that give me problems. I'll be interested to see what side-by-side comparisons of two test kits show.

BTW, I use trichlor tabs because of the CYA (cover your acid?), and that is constantly flushed out so it never builds to excess. And with the volume of Cl I need to meet NM standards (1 to 5 FC, target 3-4) tabs are actually cheaper for me (and much easier) than bleach.

Thanks again. I love this site!
 
How interesting...you have hot springs feeding your pool? How hot is the water at the source? Can you blend it with cooler water or do you just restrict the flow? Can you keep your pool temps up year round?.....I don't know your climate.

Do you have any mineral deposit issues?

How did you tap the source?
 

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Okay, I'll explain what I can. First, pix of some of our smaller pools can be seen at ojospa.com (I'm not trying to advertise here) and I'll get some of the big pool, too. The pools are all hot-spring fed, several springs ranging from 109 to 131 degrees, constant temp and flow year-round. We're open all year, people show up even at below-zero temps (we're at 6200 ft elev.). All pools are flow-through, but also pumped through sand filters, UV and ozone as well. Chlorine in big pool only. Other pools are certified as mineral "baths" so no residual required. They're drained and power-washed w/ bleach every night. I test daily for bacteria. We run bleach through sand filters so they don't turn into petri dishes. UV tubes need cleaning daily due to minerals (iron, arsenic, lithium, CaCO3). Despite our ads, mineral content in all springs is similar. Mineral on pools adds to rustic appeal of the spa, says management.

We control temp (pools range from 98 to 107, big pool at 90) with valving and 4 heat pumps. BTU source for heat pumps is overflow from pools run through heat exchangers (95 degrees downstream from pools). They provide heating & cooling for rooms, too. Big pool can act as a heat sink in the summer when necessary.

Tapping the source was a matter of putting pipes about 20 ft. down; the artesian springs just flow right out. For potable water we use cold water wells about 2 miles away.

I could go on and on...I love my job!
 
Well, that's just all very interesting, indeed.

There's little doubt in my mind that is not a wonderful place to visit....provided you would take us on an equipment tour!

Thank you for making so many of us completely jealous of your work and your facility. :mrgreen: :mrgreen:
 
Absolutely fascinating!!

May I ask what sort of bacteria testing you do? Serial dilution vials, or simple paddle indicators with Agar? Something else?

What an interesting place and setup this must me. If I could get a good water treating/testing job like that I'd be changing careers in a heartbeat.

Very cool stuff! :goodjob: :goodjob: :goodjob:
 
Our bacteria tests are package products called Enterolert and Colilert. Reagent is added to a 100ml sample, poured into a tray with multiple cells and heat sealed. After 24 hr. incubation, UV light indicates presence, number of cells glowing gives equivalent to plate count. Trained monkey could do it, so I'm qualified!

Message to all: Let me know if you ever do get out this way; I'd be delighted to give tours. Also, we just had a guest with an RC aerial camera take videos of the facility. He says he'll put it up on YouTube. I'll let you know if & when. Thanks for your interest.

Jeremy
 
http://ojospa.com said:
We've created the perfect environment for those yearning to bathe au naturale under big blue skies by day, or on a stunning starlit night, ...
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JeremyNMex said:
Also, we just had a guest with an RC aerial camera take videos of the facility. He says he'll put it up on YouTube. I'll let you know if & when.
Click to expand...
:wink:
 
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