Could I have a bad test kit for Alkalinity ?

[Mrlittlejohn]

I recently became a supporter and ordered a TF100 test kit. I have checked my water several times and the alkalinity has always read 50% high. I would read 180 and it was 120 according to my local company that re-applied my new marcite coating. They would read it with their Taylor at 120. I had read my neighbors before around 300, and they read it at 200, and of course we added acid for the amount of 200 to bring down to 120 for my pool. And then verified the change the next day. I have had 4 different occasions of almost exactly the same percentage off.

Could I be doing something wrong to get these results?


Thanks in advance for your advice,
Mike

 

[257WbyMag]

I don't think that there is anything wrong with your kit. I would trust it over others. But let me ask you this...has the water been circulating for 30 to 45 minutes prior to testing? Is your sample size exact? Are you wiping the tip of the dropper between drops to eliminate static and ensure that the drop sizes are consistent (most common cause of variances in TA testing)?

 

[duraleigh]

When the R-0009 reagent is VERY fresh, it reacts statically with the dropper tip and the drops "jump" off the tip before they are fully formed.

It's a PITA, but you need to wipe the dropper tip with a damp cloth every drop or so to elinate the static. Hold the bottle vertically to ensure you get a full size drop. That should fix it.

This condition goes away in a week or so.