Ok. I know this has been debated quit a bit on this site however, I wanted to throw in my results. I have had the Colorq for about two weeks now and ill tell you it has been very,very accurate. Now, when I first got it I just jumped right in and started testing and it was a disaster. It would be like using the tf-100 (great kit buy the way) with out knowing you have to keep mixing the drops. The colorq has very precise instructions that need to be followed and once you do, it will be dead on including the cya and the ch. At least for me it has been. Ill point out the major ones.
1. Make sure your tubes are clean. Us the brush they give you.
2. Make sure they are dry on the outside.
3. Make sure you blank before starting your group of test AND us the water and tube you blanked with for your fcl and tcl test. Be sure to hold reagent bottles straight up and down when dispensing.
4. Invert tube only once(except cor the cya test) and do not shake. Tap the tube a few times on the bottom to break any bubbles.
5.Press the button to move on to your next test BEFORE removing the tube ( they don't say why but this one seems to make a big difference. Maybe has Something to do with lighting ).
6. When doing ch and ta test, wait 20 to 30 seconds before testing. This is not in the instructions but it seems to work every time.
7. When doing cya test, invert three times and wait the FULL 2 min and then invert one more time and test IMMEDIATELY. Do not wait. About 7 test now and everyone has been between 69 and 72. The black dot test comes out as 70.
8. The chlorine test is rated for 10 ppm however, they DO outline a procedure for testing much higher levels in cases of shocking as follows :
Add 1 mL of sample water to a test tube by filling the cap ½ full. Then fill to the 5mL line with distilled or deionized water (bottled water can contain hardness) to get estimated results. Cap and mix. Blank with this diluted sample then follow the test procedure add reagent to the diluted sample. Multiply the displayed result by 5. (Not applicable for the ph test).
Seems like a lot but following these instructions you can do all test in about 6 to 7 mins with accurate results.