Which test results to believe?

[HuskerFan_1]

I have been using a color q water tester and thought that it wasn't reading correctly. The pool store that I was comparing it to is using an electronic strip reader attached to their computer. My results are way off from theirs. I am trying to lower alkalinity by lowering ph with muratic acid and then aerating. I was getting tired of running to pool store to sample my water while doing this, because I thought my tester was not working. So I bought some hth 6 way testers to keep track of my progress. To my surprise the hth strips match my color q tester very close, although I cannot test TC with the hth strips, the FC on both read close enough to assume the TC on the color q is correct. Ph, ALK, and CYA all match my color q.

I was about ready to send the color q to Lamotte, after talking to them they said they could check it out for me. Reagents I am using have 1 year left before expiring.

So my question now is do I believe my color q and the hth strips or the pool store?

 

[linen]

So my question now is do I believe my color q and the hth strips or the pool store?

Unfortunately all three of those methods can be inaccurate. You can search on this site and read about problems with all three (google search on lower left of page). We recommend a good drop based test kit that includes a FAS-DPD FC test. Follow the link in my sig on test kits, there is a note at then end of that article discussing the colorq.

 

[Bama Rambler]

As Linen said, a good drop based kit is best, but if I HAD to choose I'd go with your own testing. ColorQ's can have problems, but when they're right they're pretty good. Pool store's tests are a gamble. You never know if they're close and they may be close on one and way out on another.

You could buy a TF-50 and use it every once in a while to check your ColorQ. The kit would most likely be cheaper than sending the ColorQ back for testing.

 

[XsAllOverIt]

I would trust the ColorQ over the store results. My ColorQ results fair well with my TF100 test kit.