Trying to Figure Out What's Going On with FC

[thomearl]

Hello, can you help me figure out what's going on with my FC readings? Tested my water this past Saturday and got these readings:

FC 13
pH 7.5
CC 0
TA 100
CYA 80
CH 450

The weekend before my FC was at 8 and before that it was at 4.5. I've never had a reading so high for FC. After Saturday's test, I turned off the chlorinator on the system so the salt cell supposedly hasn't generated any since 4 days ago, but I just tested it again and get the same reading. The weather here has cooled off in the last 2 weeks, is that it? My pool temp at the moment is about 65 degrees. Please help, is something abnormal going on? Thanks.

 

[tim5055]

I'm going to guess you are getting a lot less sun on your pool. Remember, two things consume chlorine - organics and UV (from the sun).

I have reduced my pump time to just 3 hours a day while turning up the % slightly on my Stenner pump and my FC is holding in range.

 

[thomearl]

Well, atleast a lot less heat. It's still been relatively sunny, though temps have dropped about 20 degrees in the week or so. Before dropping the chlorinator to 0, it was at 50% for most of the summer. So this is normal? We've only had the house since January, so this will be our first winter with it.

 

[Richard320]

Chlorine demand goes waaaaay down in the winter. And on an overcast day, I generally lose nothing. Sounds normal to me.