PH TA Anomaly

[AimeeH]

I let the pool go green for winter. Just got my TF100 refills. PH appears purple......too high to be accurat. But, TA is measuring 40--which is where I expected based on history. Not a newbi by any means but not sure how to address this. TA doesn't need to go any lower but addressing PH will lower it?

 

[Leebo]

What’s the temp of the water??

 

[AimeeH]

It is Cold. I'd guess 65ish......

Edit. Colder. But I can't read the green thermometer. Shame on me.

 

[JamesW]

Did you add chlorine?

High chlorine can affect the color of the pH test.

Check the pH of the tap water to see if the pH reagent seems to be ok.

 

[AimeeH]

No chlorine yet extremely low PH on our tap water (but none has been added to the pool lately anyway). @Leebo would low temps be affecting the PH test?

 

[JoyfulNoise]

If you have the acid-demand drops (R-0005 or R-0015 depending on the kit), you can use those to see if the color of the pH test solution changes when you add them.

You might check for ammonia if you have a test kit for it ($8 at an aquarium shop).

 

[AimeeH]

Matt....I do not have an acid demand test or ammonia test ammonia wouldn't surprise me as I've never let the pool get this bad before and I had pretty high CYA last time I tested in the fall and Im measuring definitely less than 20 now. Since my TA is 40, can I ignore this PH reading and just proceed with SLAM level chlorine?

 

[JamesW]

Cold water won't make a difference in the test.

Test the tap water to see if the pH test works.

Rinse everything well and retest the pool water.

 

[Leebo]

pH tends to increase in cold water and will decrease when the water warms up. Our pool does something very similar to what you’re seeing every winter. I suspect it’ll drop somewhat as the water warms up.