TA / CYA going up after Rain

[ubernoob]

Hey Guys,

Very confusing situation, last week when i tested my water i was at a TA of 60, CYA of ~60.
Re-tested today after gaining about an inch worth of rain water, and my TA is at 80, CYA of ~80.
Testing was done at the end of the day, when the pump was on for >5 hours.

Didn't add any chemicals in between other than liquid chlorine...

Is there an explanation to this madness or is there something else going on in my pool?
Also, pool didn't get any use during the week.

Thanks!

 

[HermanTX]

CYA doesn't increase unless you add it. Could you have added some several days ago? Sometimes it takes CYA a long time to register on a test after adding to the pool. I sometimes wait 5 days to see the effect of adding stabilizer.

Could tap water have been added - like through an autofill? That can carry high amounts of Alkalinity.

There is another possibility - testing error. I find if something is out of wack from a previous test - I go back and retest it and may test again the very next day. Sometimes your pool sample can get wonky - like if you take your sample but then leave it in the sun for a couple hours then remember to go test it.

 

[ubernoob]

Hmm ill give it another shot tomorrow. I have a in-line chlornator, but it's been turned off and empty since last season.
I did add some water last week because i was running below the skimmer, so that could explain the TA.

Does water temperature have something to do with it? We were getting beautiful weather last week (75f on avg), but it's suddenly taken a turn and gotten much cooler (~64f on average) this week.

 

[HermanTX]

Does water temperature have something to do with it? We were getting beautiful weather last week (75f on avg), but it's suddenly taken a turn and gotten much cooler (~64f on average) this week.

When testing CYA and it is cold water, it is best to let it warm up to room temp.