LaMotte ColorQ Water Tester

[donaldm823]

Does anyone have experience with LaMotte's new ColorQ water test system. It is a colorimeter system vice test strips and uses liquid regents, and then tests 6 different pool chemistry values based on a measured color through this electronic device. (Free CL, Total Chlorine, pH, TA, CH, CYA. ) I am particulary interested in the hardness (CH) accuracy.

[tenax]

haven't seen anything on this forum in my many roamings except the info here if you go some threads into it:

http://www.poolforum.com/pf2/showthread.php?t=7394

[Poolsean]

Just got one from LaMotte. I will be trying it out this week. I will let you know what I think after I get some use of it.

[CelticDaddio]

How do you like the ColorQ so far?

Ed


Just got one from LaMotte. I will be trying it out this week. I will let you know what I think after I get some use of it.

[waterbear]

Just got an email back from LAMotte tech support about the ColorQ. This is what they had to say:
The ColorQ has accuracy of ± 0.1ppm on chlorine and pH, ± 15ppm on alk,
and ± 20ppm on hardness and cya. The cyanuric acid test is a difficult
one with a meter like the ColorQ, since it is a turbidity style reaction.
(it gets you in the ballpark on cya). The chlorine and pH tests are great.
The alkalinity test has been performing very well, my ColorQ has given me
readings within ± 5 to 10ppm on alk. Hardness is another tough one, but
the ±20ppm isn't so bad when you consider the wide range of hardness from
200 - 400ppm. So all in all, it is actually a great meter for that price.

I feel this is a very honest answer and based on it and knowing LaMotte's reputation I would say this is a worthwhile unit for the home pool owner! A drop counting test for calcium hardness is +/- 10 ppm for the Taylor reagents so this is not that bad and the standard disapprearing dot test for CYA is extremely subjective. My original question to LaMotte was concerning how well the ColorQ compares to more expensive colorimeters that usually cost in the neighborhood of $1000!

[MikeInMo]

Please add me to the list as well anxiously waiting to hear on how well these work.

I was too late to get Ben's kit last year and was planning on getting a good drop kit, (probably the kit offered at troublefree.com), but with the number of tests included in the colorq with somewhat reasonable refill prices...
But who am I kidding, it's the GEEK factor that has me looking at this.

All I currently have is the Walmart 6-way and am quickly running out of my CYA test so I need to replace the kit soon.

Last question....Where can you buy the Colorq? I've only seen 1 place and he's posted that he's backordered for 2-3 weeks...any other ideas where it can be purchased?

Thanks,
Mike

[donaldm823]

Please add me to the list as well anxiously waiting to hear on how well these work.

I was too late to get Ben's kit last year and was planning on getting a good drop kit, (probably the kit offered at troublefree.com), but with the number of tests included in the colorq with somewhat reasonable refill prices...
But who am I kidding, it's the GEEK factor that has me looking at this.

All I currently have is the Walmart 6-way and am quickly running out of my CYA test so I need to replace the kit soon.

Last question....Where can you buy the Colorq? I've only seen 1 place and he's posted that he's backordered for 2-3 weeks...any other ideas where it can be purchased?

Thanks,
Mike

Checkout lamotte.com web site (the manufacturer). The ColorQ is listed in the pool testing section under new products.

As for the GEEK factor-I too suffer. I have been very happy with the tester. It comes with 140 individual tests (except CYA which was 50 pills that you crush), which should last you the pool season. I bought a kit refill for $45 since I knew I would be testing 2x per day for a while until I get some history on using chlorox daily adds (just shifted this year). The tester uses liquid reagents (5 drops)(CYA uses a pill you crush) in a 5ml test tube that you insert into the tester, so the cleanup is very quick. The tester reads out in two decimal places-although I doubt if it really is that accurate. Also chlorine goes up to 10ppm. Comes in a nice travel kit. Actual electronic tester is about the size of your hand and uses a regular 9v battery

[salinda]

Don,

Where did you get it? LaMotte told me to order from a local pool supply store (they all carry Taylor though) or from AskAlanAQuestion.com.

[MikeInMo]

Alright...does ANYONE have any additional comments on this tester???

Getting ready to pull the trigger and want to make sure no buyer remorse hits in.

Thanks!

[MikeInMo]

Well I couldn't wait so it's GEEK AWAY and I ordered the tester. I live about 45 minutes from the closest pool store so hopefully this make those trips for testing unnecessary, plus no hard sell for chemicals. Still have a fair number of drop tests left so I can't wait to compare.

[salinda]

I didn't get a good feeling from the AskAlanAQuestion website, so I found out I could order one directly from LaMotte. I went to their website and called the number off of the contact us link. They are backordered a little because they have been very popular.

[MikeInMo]

Last night the ask alan website was showing a 2-3 week back order notice but when I looked at it today the notice was removed. I'll give it 4 or 5 business days and if haven't received it I'll escalate.

[Poolsean]

I used mine afew times this week. Works pretty good and easy to use. Takes away the human error factor, as long as you can count drops. The meter measures then shows you the test result.
Very nice but a little bulky to carry in my suitcase when I travel.
I was just in Phoenix (110 degrees!!!! WOW!) and the tester worked just fine. It didn't melt in my hands...

[donaldm823]

Well here goes my full review-had the new LaMotte ColorQ water tester now for 3 weeks. Love the tester. Initially had a problem with Hardness accuracy, but LaMotte tech support replaced the unit quickly. The unit cost $129 plus shipping and comes with 140 tests (liquid reagents) except CYA (uses pills which) there are 50. A refill package is in the $45 range, but you get enough chemicals with the tester itself to last a pool season without a refill kit.

The unit comes in a handy test kit rubber bag (zippered) which hold the 4 test tubes that come with the unit, all of the reagents, and of course the electronic device (colorimeter)(size of your hand) which measures the color intensity of each test which is correlated to a ppm reading that reads out on a digital meter. Unit is powered by 2 AA batteries and is guaranteed for 6 months.

You basically add 5 drops of a specific liquid reagent based on the test performing (one test tube per test), and they put the 5ml tube into the unit and read the tests in sequence, replacing the test tubes for each tests. You read a blank at the start (pool water) which calibrates the colorimeter. Have tests for free and total Cl up to 10ppm, pH, TA, CH hardness, and CYA.

I am very please with the unit and its accuracy. Have compared all of the tests results against by Ben Pool Solution kit, and all the results were within the accuracy accept for Hardness. Since they just replaced the unit for the hardness issue, I do not have a lot of run time, but the hardness result was 220ppm and my Taylor reports a 260-280ppm-close enough for my use

Highly recommend if you are tired of all of the titrant kits. At $129 not a bad buy. Checkout LaMotte.com website under pool/spa water/new products. They also sell the refill kits as well as spare test tubes

[salinda]

Don,

What was the issue with your CH test? I just used my new ColorQ for the first time and pH, alk, CH, and Cya were all off both from Ben's kit and from fairly recent pool store tests. CH was WAY off. My CH is high, holding steady at over 500 for a couple of years now, both by my measurements and the pool store. The Lamotte thing measured it at 235!
We have had no rain in CA for months and I don't backwash because I have a cartridge filter, so there is no way the CH could have dropped, especially this much. I'll be calling them today and give you all an update.

[salinda]

Well, I just got off the phone with them and the instructions that are so clear in many places are completely wrong on one thing: The cap must be ON for the blanking test.

I will now be retesting and calling them back.

[donaldm823]

Well, I just got off the phone with them and the instructions that are so clear in many places are completely wrong on one thing: The cap must be ON for the blanking test.

I will now be retesting and calling them back.

Salinda:
What did you resolve with the CH?? Is it still reading 50% of the Taylor?

I also got colorQ CH results lower than my Taylor titrant. Yesterday's reading was 199 with the colorQ and 280 with Taylor. I assumed the colorQ was correct.

LaMotte as part of their troubleshooting, sent me a 250ppm test standard for me to measure at home. The ColorQ read 230 and the Taylor read 290. They suspect interference from metal in my pool water although my copper measurement was no detectable copper. I do have high phosphate in the water and have used Jack's as treatment. Anyway, I gave up, and use the ColorQ CH measure as an approximation as it is a good trending device. All of the other analysis were accurate based on my other tester and the poolstore

[salinda]

My retest with the cap on for blanking gave the same numbers, probably because I tested inside so the lighting didn't interfere much. Almost all of the numbers were off for me, including alkalinity, pH, cya, and CH.

They requested me to send them a sample of my pool water at their expense. I shipped it out last Friday, but with the holiday on Wednesday I expect it will be about a week before I can provide you with an update.

So far, I have been impressed with their customer service, but I will have to request a refund if the kit can't test MY pool water.

[donaldm823]

My retest with the cap on for blanking gave the same numbers, probably because I tested inside so the lighting didn't interfere much. Almost all of the numbers were off for me, including alkalinity, pH, cya, and CH.

They requested me to send them a sample of my pool water at their request. I shipped it out last Friday, but with the holiday on Wednesday I expect it will be about a week before I can provide you with an update.

So far, I have been impressed with their customer service, but I will have to request a refund if the kit can't test MY pool water.

ok-thanks for the return. I am very interested in what you find as your problem is very similar to mine.

I also found tech support excellent and they stay with you. They were able to resolve all of my issues (except the nagging doubt about CH accuracy). My other analysis were resolved by technique as the tests are very subseptible to holding the titrant bottles exactly vertical and ensuring the amount of sample is exactly at the line and ensuring no cross contamination between reagents (big fingers!!). Also my first colorQ had a bad CH reagent (something to do with the stabilizer)-which they replaced. (They reported a bad CH2 reagent lot last month). Again I was very happy with their tech support and even though by current CH results are low, they are still within the accuracy expected (+/- 20 ppm). But, before I add any calcium for my low CH, I would like to hear your resolution. As of now, I am assuming my colorQ is providing a CH result that is low by 30-40ppm.

[salinda]

Also, my CH is beyond the range of the test, but the tech support told me the test should reflect this by giving me a result on the high end of the range. It is currently giving me a result in the middle.

[salinda]

Update...

Here is a response from LaMotte:
------------------------------------------------
Dear Linda,

Our lab has been working with your sample. Your hardness values are well beyond the recommended levels. This high hardness value in your water is buffering the sample and interfering with the test reactions.

Lowering your hardness is necessary to prevent scale and protect your hardware and equipment. Once the hardness values are in the proper range, test interferences will be eliminated.

I will send you a vial of our Insta-Test strips @ no charge to use while you lower your hardness. I will also include a set of replacement chemicals for your ColorQ. Please let me know your shipping address.

Thank you for your patience. I look forward to your reply.

-------------------------------------

I sent the following response. Note that my CH, although high, is only 570. The colorQ is supposed to test to 400 so it doesn't have to be much over to interfere with the kit. Too bad....

---------------------
Charlie,

Thanks so much for the response.

Right now, I am handling the high hardness by maintaining a low TA number. I have had now scale on my equipment for the 3 years that my hardness has been high, so it is not problematic. My pool is about 35,000 gallons, so reducing hardness via the recommended drain and refill would be a real hardship, especially this year.

Should I return the ColorQ and try again in future years after I do a major drain/refill?

[Ront]

Please add me to the list as well anxiously waiting to hear on how well these work.

I was too late to get Ben's kit last year and was planning on getting a good drop kit, (probably the kit offered at troublefree.com), but with the number of tests included in the colorq with somewhat reasonable refill prices...
But who am I kidding, it's the GEEK factor that has me looking at this.

All I currently have is the Walmart 6-way and am quickly running out of my CYA test so I need to replace the kit soon.

Last question....Where can you buy the Colorq? I've only seen 1 place and he's posted that he's backordered for 2-3 weeks...any other ideas where it can be purchased?

Thanks,
Mike


I know I am a little late on answering this question you have, but I will tell you anyway.

After reading about the ColorQ on here and other places, I decided to order it. I ordered it from askalanaquestion.com , the first good thing about this site is that they accept paypal. Then, I believe they said that the ColorQ was backordered 1 week or more.

Well, I ordered it on Wednesday, and received it on Thursday, less than 24 hours later.........not bad for a "backorder". Of course this also depends on where you live, I believe the kit is shipped directly from Lamotte located in Maryland, I am in NJ, so standard ups ground is 1 day.

Anyway, I am very impressed with any site who ships out your order same day, especially since no "premium" shipping charge was paid. So, 2 thumbs up
to askalanaquestion.com and Lamotte!!

[Ront]

I didn't get a good feeling from the AskAlanAQuestion website, so I found out I could order one directly from LaMotte. I went to their website and called the number off of the contact us link. They are backordered a little because they have been very popular.


See my previous reply, askalanaquestion.com has excellent service.

[salinda]

Great! It is nice to know there is more than one source.

Unfortunately, I am not able to use my ColorQ (see above). If you have high CH, think twice about using this system. Mine is in the 500-600 range, which people on this forum consider to be more than manageable. This is only a bit over the range of the CH test in the ColorQ, but it is "buffering" my results per LaMotte. I am pursuing a refund right now.

[MikeInMo]

Well I ordered the ColorQ a few weeks back and it is satisfying my 'geek factor' and more. First it should be noted that while I try to be somewhat precise about the water I place in the tubes (I've found it a lot easier to go under and then add drop by drop from the sample bottle) I just consider myself lucky to get the reagents in the tubes, let alone trying to ensure uniform drop size. [I often do this in the pool and with kids splashing water and waves, and with my aging eyes I'm just happy to hit the opening.] I imagine my numbers would be better if I ensured this uniformity.

Using the cheap OTO chlorine tests I could never figure out which shade of yellow I really had (and was limited to 5ppm TC as well). The ColorQ really has alleviated my concerns in this area providing a very accurate reading on the FC, CC, and TC amounts. The PH readings are virtually spot on with my other drop tests. The ALK tests are in-line with drop tests, maybe a tad on the low side.

I too contacted customer service at LaMotte re: the CH readings. Charlie is excellent to work with and I have never been on hold for an extended period of time. They sent me out a new set of CH reagents (at no charge) but my values stayed the same. [They told me I did not have a problem lot and they must have been correct.] I am running about 70 points low compared to my drop tests. [ColorQ shows 200 and drops show 270.] I can live with this now that I have figured out the adjustment amount. Having a gunnite pool I was concerned I was too low but everything seems to work fine.

I really enjoy how precise the tester is and the ease & quickness of the tests. No more trying to remember was that drop 20 or 21 I just put in. All in all I definitely recommend it.

Mike

PS. It also satisfies my mad scientist cravings!

[salinda]

I agree that the system is easy to use but at this point I CANNOT recommend the ColorQ for people with high CH. According to Lamotte, the high Calcium levels throw off ALL the other numbers. In my case, this was definitely true. I am still pursuing a refund.

[Amir]

OK. Here is my experience with the color Q. Got it a couple of weeks ago. Like the machine. All the test look good EXCEPT CYA! I have a CYA of about 50 and the machine shows 3 or 7 or 9 etc! After MANY conversations with tech support I was told that this is an issue with the machine and it is water temperature dependent. The temperature should be near 75 degree (mine is 81) to be accurate. The last conversation with tech support we left it at shipping the machine back to see if they can do better or receive a refund.
Regards
Amir

[Ront]

OK. Here is my experience with the color Q. Got it a couple of weeks ago. Like the machine. All the test look good EXCEPT CYA! I have a CYA of about 50 and the machine shows 3 or 7 or 9 etc! After MANY conversations with tech support I was told that this is an issue with the machine and it is water temperature dependent. The temperature should be near 75 degree (mine is 81) to be accurate. The last conversation with tech support we left it at shipping the machine back to see if they can do better or receive a refund.
Regards
Amir


I am having the same problem with the CYA test. When I received the unit, my CYA level was around 40, based on the Pool Solutions test. About a week before, I installed a SWG, and following their advice, I added 4 Lbs. of CYA to raise the level towards 80.

The first couple of CYA tests with the ColorQ, was showing between 27 & 31.
The PS CYA test is showing around 60-70. Well after just adding 4 Lbs., I can know for a fact that the ColorQ test is way off.

But anyway, I am just going to test the CYA level several more times in the next week, and as long as the results remain consistent, I can then easily apply the correction factor. If the results start bouncing all over, I'll have to make the decision whether to keep it or not.

Other than that, all the other numbers look good. We will see what happens!!

[donaldm823]

Well I ordered the ColorQ a few weeks back and it is satisfying my 'geek factor' and more. First it should be noted that while I try to be somewhat precise about the water I place in the tubes (I've found it a lot easier to go under and then add drop by drop from the sample bottle) I just consider myself lucky to get the reagents in the tubes, let alone trying to ensure uniform drop size. [I often do this in the pool and with kids splashing water and waves, and with my aging eyes I'm just happy to hit the opening.] I imagine my numbers would be better if I ensured this uniformity.

Using the cheap OTO chlorine tests I could never figure out which shade of yellow I really had (and was limited to 5ppm TC as well). The ColorQ really has alleviated my concerns in this area providing a very accurate reading on the FC, CC, and TC amounts. The PH readings are virtually spot on with my other drop tests. The ALK tests are in-line with drop tests, maybe a tad on the low side.

I too contacted customer service at LaMotte re: the CH readings. Charlie is excellent to work with and I have never been on hold for an extended period of time. They sent me out a new set of CH reagents (at no charge) but my values stayed the same. [They told me I did not have a problem lot and they must have been correct.] I am running about 70 points low compared to my drop tests. [ColorQ shows 200 and drops show 270.] I can live with this now that I have figured out the adjustment amount. Having a gunnite pool I was concerned I was too low but everything seems to work fine.

I really enjoy how precise the tester is and the ease & quickness of the tests. No more trying to remember was that drop 20 or 21 I just put in. All in all I definitely recommend it.

Mike

PS. It also satisfies my mad scientist cravings!

So Mike-which test do you think is accurate (Taylor drops or colorQ). I also get 205ppm from ColorQ and 290ppm from Taylor and was considering adding more CaCl. Leslie gets 350ppm. I thought it may be some pool water interference from some unknown and just maybe colorQ was the accurate one. I have an inground concrete pool (1 yr old). Tech support was great and replaced both my meter and also the CH2 reagent. At that point, I thought the colorQ was the accurate one. Either way, I think colorQ is a great tester and am happy I bought one

[Amir]

Ront,
My cya reading with colorQ has not gone above 9 where my cya should be about 50. According to laMotte CYA is temperature dependent so you can not just add a number to what you get from the colorQ to be accurate since the water temperature varies with the season . In order to get this machine to work right they should take into account other factors in addition to color and the machine needs to be more sophisticated and probably more expensive. I for one would have paid another $50 for a more reliable machine. I guess if you think of the machine as a test fro cl, alk, ph and ch only it is not bad.
Regards

Amir

[salinda]

I got an RMA number and I am now returning mine. I am VERY skeptical about the accuracy of this meter. All of the results were off for me by quite a bit. Nice idea, poor execution.

[Ront]

Ront,
My cya reading with colorQ has not gone above 9 where my cya should be about 50. According to laMotte CYA is temperature dependent so you can not just add a number to what you get from the colorQ to be accurate since the water temperature varies with the season . In order to get this machine to work right they should take into account other factors in addition to color and the machine needs to be more sophisticated and probably more expensive. I for one would have paid another $50 for a more reliable machine. I guess if you think of the machine as a test fro cl, alk, ph and ch only it is not bad.
Regards

Amir


It is very easy to change the Temp of a 5 ml sample. In order to maintain consistency, I have reduced the temp of the sample to 75, very simple by dipping tube into cooler water for a couple seconds. Anyway, 6 sucessive tests have been between 29-31 for the CYA. So, while it may be showing low, at least it is showing low consistently. This is not a big deal, since the CYA test does not need to performed on a regular basis as does CL & pH.

[Amir]

I wonder why Taylor CYA test that uses liquid melamine reagent is not so temp sensitive. That test also depend on the water to get "cloudy" but has good results consistently.
Amir

[Amir]

Ront,
If you get 29 with the correct water temp and the CYA should be 60 and 70, there is something wrong with that machine. They should not advertise CYA accuracy if you do everything right and the results are off by that much.
Amir

[waterbear]

Ront,
If you get 29 with the correct water temp and the CYA should be 60 and 70, there is something wrong with that machine. They should not advertise CYA accuracy if you do everything right and the results are off by that much.
Amir
Please reread my post near the beginning of this thread where I posted what tech support at LaMotte said about the meter. CYA is +/- 20 ppm so your reading of 29 is within spec. It can be as high as 49 and you stated that your CYA should be around 50 ppm. When doing any kind of water testing you have to look at the precision of the test. The meter is probably more accurate than a 'disappearing dot' test any day within the limits of it's accuracy since it removes the subjective element of 'when has the dot actually disappeared?" You can have 3 people do a disappearing dot test on the same sample and they can get readings that are not even close to each other! Common testing methods for CYA as used in home test kits (and even some very expensive professional ones) are a rough guide at best and should be used as such. It's really not appropirate to say "my cya is 70 ppm" since it can be off by as much as 30 ppm with conventional testing methods. At best you really only have a ballpark figure of where it is with the types of tests included in most water test kits.
As far as the calcium hardness problem, that seems to be a limitation in LaMotte's chemistry that is used with colorimeters. We use a Waterlink Express at work that uses vials of dry reagents. The upper limit of the CH test is supposed to be about 500 ppm but if the hardness is higher than that the test will still only report about 450-500 ppm. I have spoken to LaMotte tech support on this and they suggested to titrate when I got high calcium readings with the Waterlink. Interestingly, LaMotte does offer kits that include calcium hardness titration tests also. Using a meter certainly speeds up testing but does not necessisarily REPLACE other forms of testing. You need to know the limits of the equipment and use the apporpriate test under the appropriate conditions. Don't throw the baby out with the bathwater!

Just my 2 cents! (And no, I don't have a ColorQ. I use Taylor chemistries to test my own pool! I still think the ColorQ is a viable tool in water testing when used properly.)

One final note about CYA testing. Temperature does affect the test to some degree whether you use liquid or dry reagents as does how long you let the sample stand before testing. That is why I have said in several previous posts about the Taylor test to make sure the sample is between 70-80 degrees and to let the sample stand for about 5 minutes after shaking it for 30 seconds and to shake it again to disperse the precipitate before dispensing it into the view tube. I suspect that if you let the CYA sample sit for about 3 minutes before reading it in the ColorQ you will find that your CYA readings are more in line with the Taylor one.

[Amir]

Waterbear,
thanks for the comment. My CYA should be around 50. I have never been able to get a reading form colorQ more than 9! Retesting the same sample gave me different measurements and surprisingly the water seems to get less cloudy the longer it sits! Maybe it gets warmer. This was not apparent with the liquid reagent and the dot. Temp here is over 90 in daytime! I have followed the instruction to the letter using a stopwatch - I am surprised that lamotte does not ask to shake the sample but just turn it upside down three time and once before placing it back in the tester. the pool was plastered and filled in June. The only thing in the pool has been trichlor tabs, bleach, CYA(6 lbs), Muriatic acid and baking soda. temp 80, PH 6.6, TA 87, CH200, CL 3.8, CYA ~50. I hope there is something wrong with the meter since I really like it. I might even keep it just for the other tests.
Regards

Amir

[waterbear]

inverting the vial 3 times is the correct procedure but you have to make sure the tablet is fully dissolved. Also high water temp will give a lower reading since the precipitate will be more soluable so having the sample at the correct temperature is important. We get many customers who leave a water sample in their car all day! (I TRY to tell them that this will affect the test results but some of them just don't care.) The first thing I always do is to take the temp of the sample and if it's above 80 degrees I stick it in our freezer at work for a few minutes to bring it down before I test it.

[donaldm823]

inverting the vial 3 times is the correct procedure but you have to make sure the tablet is fully dissolved. Also high water temp will give a lower reading since the precipitate will be more soluable so having the sample at the correct temperature is important. We get many customers who leave a water sample in their car all day! (I TRY to tell them that this will affect the test results but some of them just don't care.) The first thing I always do is to take the temp of the sample and if it's above 80 degrees I stick it in our freezer at work for a few minutes to bring it down before I test it.

I second Waterbear's comments and add that based on my 2 months experience with the colorQ, you need to let the CYA sample sit for at least 5 minutes before reading or it will read low and get that sample below 78F. Also, if analyzing samples with chlorine higher than 4ppm, you need to let all of the samples with reagent added sit for a minimum of 2 minutes before reading with the meter or you may get erroneous readings on FC, TC, and pH reading. My CH always reads low as compared to Taylor, but it's still inside the +/- 40ppm window

[Ront]

Please reread my post near the beginning of this thread where I posted what tech support at LaMotte said about the meter. CYA is +/- 20 ppm so your reading of 29 is within spec. It can be as high as 49 and you stated that your CYA should be around 50 ppm. When doing any kind of water testing you have to look at the precision of the test. The meter is probably more accurate than a 'disappearing dot' test any day within the limits of it's accuracy since it removes the subjective element of 'when has the dot actually disappeared?" You can have 3 people do a disappearing dot test on the same sample and they can get readings that are not even close to each other! Common testing methods for CYA as used in home test kits (and even some very expensive professional ones) are a rough guide at best and should be used as such. It's really not appropirate to say "my cya is 70 ppm" since it can be off by as much as 30 ppm with conventional testing methods. At best you really only have a ballpark figure of where it is with the types of tests included in most water test kits.
As far as the calcium hardness problem, that seems to be a limitation in LaMotte's chemistry that is used with colorimeters. We use a Waterlink Express at work that uses vials of dry reagents. The upper limit of the CH test is supposed to be about 500 ppm but if the hardness is higher than that the test will still only report about 450-500 ppm. I have spoken to LaMotte tech support on this and they suggested to titrate when I got high calcium readings with the Waterlink. Interestingly, LaMotte does offer kits that include calcium hardness titration tests also. Using a meter certainly speeds up testing but does not necessisarily REPLACE other forms of testing. You need to know the limits of the equipment and use the apporpriate test under the appropriate conditions. Don't throw the baby out with the bathwater!

Just my 2 cents! (And no, I don't have a ColorQ. I use Taylor chemistries to test my own pool! I still think the ColorQ is a viable tool in water testing when used properly.)

One final note about CYA testing. Temperature does affect the test to some degree whether you use liquid or dry reagents as does how long you let the sample stand before testing. That is why I have said in several previous posts about the Taylor test to make sure the sample is between 70-80 degrees and to let the sample stand for about 5 minutes after shaking it for 30 seconds and to shake it again to disperse the precipitate before dispensing it into the view tube. I suspect that if you let the CYA sample sit for about 3 minutes before reading it in the ColorQ you will find that your CYA readings are more in line with the Taylor one.


Yes, I understand the +/- 20ppm factor. So, during my testing, as long as I am getting consistently the same results, I can live with that. and now 6 or seven sucessive tests have been between 29-31 ppm. If I was getting wildly ranging results, that is a different story.

[Amir]

Donald,
don't you think LaMotte should or would have indicated in their instructions the longer length of time for samples. I can understand that they want to make it as simple as possible, but at least a footnote? last night I put a sample of the water with a thermometer in the refrigerator until the water was at 75F and tested for CYA according to their test procedure. The results was a CYA of 12. ups picked up the unit along with a sample of my water. I hope that this problem is just specific to my colorq and other unit or the replacement one will be more accurate.
Regards

Amir

[donaldm823]

Donald,
don't you think LaMotte should or would have indicated in their instructions the longer length of time for samples. I can understand that they want to make it as simple as possible, but at least a footnote? last night I put a sample of the water with a thermometer in the refrigerator until the water was at 75F and tested for CYA according to their test procedure. The results was a CYA of 12. ups picked up the unit along with a sample of my water. I hope that this problem is just specific to my colorq and other unit or the replacement one will be more accurate.
Regards

Amir

Amir
Understand your frustration, and yes LaMotte could improve the instructions after some run time. I suspect they were not aware of the intricacies of this new tester. I for one learn something new week about how to make my analysis results repeatable. Just today, I resampled for CYA after getting a 25ppm result after a long string of 38ppm results for the past month. Today, I shook the sample vice going up and down 3x, and got a 45ppm result, which is exactly what my Talor black spot test indicates. I believe based on other forum threads, that the CYA sample is the "toughest" for the colorQ since it really is a turbidity test of sediment vice a chemical reaction that results in a color

[salinda]

Evan,

I loved the process of the colorq, but hated the results. Also, they never told me to let the samples sit with the reagents for 2 minutes. They never mentioned that. In fact, I sent them a water sample. They claim that my "high" CH is throwing off ALL the results. That is my experience. They were all way off, not just CYA and CH. Everything was wrong and by a lot. Maybe if I had tried to let the samples sit, it would have worked. Since I was never told this, I returned the kit for a refund.

I really wanted the colorQ to work out. Maybe I will try it again when I eventually lower my CH.

[Amir]

Here is the latest update. I sent the colorq back with a sample of water. I called them yesterday and they said that they tested the machine and some costants were not correct and they are shipping me a new one that has just been tested. Hope this works out. I like this machine!
amir