CH went from 300 to 230 in 24 hrs

[sirena]

Hello,

The CH dropped from 300 yesterday to 230 today. Is this common? If so, what effects can it have, if any?

Yesterday's numbers:

FC = 5
pH = 7.4
TA = 100
CH = 300
CYA = 30
Temp = 80

I added 580 oz of 6% bleach to bring FC to 13 (I feel like I'm in shock mode all summer).

Today's numbers:


FC = 9.5
pH = 7.6
TA = 110
CH = 230
CYA = 30
Temp = 86

Thanks for any advise.

 

[Richard320]

I suspect testing error.

Calcium doesn't just disappear. The only way it went down was if you drained and refilled a quarter of your pool. But CYA didn't drop the same amount, so you obviously didn't drain.

I'd actually be suspicious of both those CH results, since Phoenix is noted here on the forum as having very hard water with very high CH readings.

 

[AquaDoctorLLC]

Your pool rose 6 degrees overnight????

What are you using to test your water? Test strips? Taylor?

 

[sirena]

I thought it was a testing error also, so tested it twice. I haven't drained any and Phoenix does have hard water. We had a little rain overnight - less than 1/2 inch. CH has been around 300 for about a month now. It was much higher.

Using the Taylor test kit. Yesterday's temp is probably an error as the thermometer is difficult to read. Since it was overcast all day yesterday, rain overnight, and temp this a.m. is 86, it would make sense that I misread it and was probably 90.