I just purchased a house with an existing pool and learning more and more about my pool, but still have many questions. I purchased the LaMotte ColorQ 7 Plus test kit. I have run several tests with my tester, but have also taken several samples to a local pool store. I'm finding some discrepancies and puzzled what to make of them. I recently shocked the pool with calcium hypochlorite due to nearly non-existence of free chlorine with a bit more combined chlorine. I added the cal-hypo Monday evening and found free chlorine of 5.64PPM and total chlorine of 6PPM on my ColorQ. I took a sample to the pool store where they found both free chlorine and total chlorine to be both 7 PPM. I'm not exactly sure what the brand of testing they are using in the store, but it is a dip stick and colorimeter. They also have a Taylor test station that requires human interpretation, but he instinctively tossed the remainder of the sample after dipping. I find it odd that the ColorQ shows 5.64PPM when their test shows 7PPM. Whose tests should I believe?
ColorQ vs pool store
- Thread starter bigRoN18
- Start date
Re: LaMotte ColorQ Water Tester
I'd believe their tests. My ColorQ reads FC low also. TF-100 reads it higher by about 2 ppm consistently. I use both tests each week. Since I'm a little anal, I test every other day (New Pool Owner) with my ColorQ due to convenience and quantity of drops. I test each weekend with the TF-100. I find that FC is off a little, Alk is pretty dead on with both tests. I find my CYA is pretty close to dead on with both tests. pH is a visual with the TF-100 so I like my ColorQ results and they appear to be right on based off of my visual inspections. I find that my CH is 200 ppm higher with the TF-100, but the good thing is each time I've tested, it appears to be consistent in trend which IMO becomes comforting. As they indicate throughout these threads, you'll know your pool over time and you'll know visually if things are good or bad. My hot tub throughout the winter has looked sparkling clear, all due to TFP. I wouldn't do it any other way and I've only been here for 5 months. I'm only one user of the ColorQ, so take my results as one data point and not as gospel!
I'd believe their tests. My ColorQ reads FC low also. TF-100 reads it higher by about 2 ppm consistently. I use both tests each week. Since I'm a little anal, I test every other day (New Pool Owner) with my ColorQ due to convenience and quantity of drops. I test each weekend with the TF-100. I find that FC is off a little, Alk is pretty dead on with both tests. I find my CYA is pretty close to dead on with both tests. pH is a visual with the TF-100 so I like my ColorQ results and they appear to be right on based off of my visual inspections. I find that my CH is 200 ppm higher with the TF-100, but the good thing is each time I've tested, it appears to be consistent in trend which IMO becomes comforting. As they indicate throughout these threads, you'll know your pool over time and you'll know visually if things are good or bad. My hot tub throughout the winter has looked sparkling clear, all due to TFP. I wouldn't do it any other way and I've only been here for 5 months. I'm only one user of the ColorQ, so take my results as one data point and not as gospel!
Even with it's quirks, the ColorQ is generally more reliable than a pool store. Pool store test results can be wildly wrong more often than you might suspect. The test strips read by an electronic reader tests tend to have many more problems than most. But even if they were using the Taylor test station, you can't generally depend on their results. It is important to do your own testing, which will be more consistent than most pool stores after only a little practice.
Consistent is the most important thing here. Even if your results are off in an absolute sense, getting results that are off by about the same amount each time is more important than being right on the correct number. Pool store tests results tend to vary all over the place, which is worse.
If you post a full set of test results I can give you more specific advice. Still, generally speaking having CC of 0.36 isn't that big a deal, especially if it happens right after the FC level has been too low. All you should need to do is to maintain normal FC levels for a day or two and the CC should go away. However, the details depend on some of your other numbers, such as PH and CYA levels.
Consistent is the most important thing here. Even if your results are off in an absolute sense, getting results that are off by about the same amount each time is more important than being right on the correct number. Pool store tests results tend to vary all over the place, which is worse.
If you post a full set of test results I can give you more specific advice. Still, generally speaking having CC of 0.36 isn't that big a deal, especially if it happens right after the FC level has been too low. All you should need to do is to maintain normal FC levels for a day or two and the CC should go away. However, the details depend on some of your other numbers, such as PH and CYA levels.
OK, pool results for my pool
ColorQ Results:
FC-1.48 TC-1.48 pH-7.4 ALY-43 CH-179 CYA-51 TEMP-70
TFT100
FC-2.00 TC-2.50 pH-7.4 ALY-60 CH-220 CYA-60 SALT-2600 (added 2 40lb bags last night and will start up SWG tonight - should be on low threshold of salt)
results are fairly consistent each time I test both kits. ColorQ always goes low on chlorine, CYA and CH. pH seems to be dead on along with CYA. The TFT100 test with CYA could have been a little lower. Thought I still saw black dot at 60. I'll add a little alkalinity regardless and adding a little more stabilizer. Pool looks really good except needs DRAMATICALLY cleaned each day due to too many trees. The good thing is that I'm finally convincing Lana that we may need to get rid of a couple more.
ColorQ Results:
FC-1.48 TC-1.48 pH-7.4 ALY-43 CH-179 CYA-51 TEMP-70
TFT100
FC-2.00 TC-2.50 pH-7.4 ALY-60 CH-220 CYA-60 SALT-2600 (added 2 40lb bags last night and will start up SWG tonight - should be on low threshold of salt)
results are fairly consistent each time I test both kits. ColorQ always goes low on chlorine, CYA and CH. pH seems to be dead on along with CYA. The TFT100 test with CYA could have been a little lower. Thought I still saw black dot at 60. I'll add a little alkalinity regardless and adding a little more stabilizer. Pool looks really good except needs DRAMATICALLY cleaned each day due to too many trees. The good thing is that I'm finally convincing Lana that we may need to get rid of a couple more.
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