FC Loss Seems High, No CC

[demedeirosa]

Hi All,

I've got a 21ft above ground pool in southern New England. Have been following TFP guidelines and have been quite successful so far. Testing with a Taylor K-2006C kit.

I have noticed lately that my FC seems to drop significantly in 1 day. Data below:

1. 7/26 - FC=0, CC=0, Added 64oz of 12.5% Bleach (Liquid Shock)
2. 7/26 - 6AM, FC=5, CC=0, CYA=50
3. 7/28 - 6AM, FC=1.5, CC=0

Other Parameters taken on 7/24

• pH = 7.8
• TA = 100
• CH = 120

This loss of FC seems very fast to me, although I am not positive, any thoughts? The weather has been between 75-89 the last few weeks.

The other strange thing is that I have never once had a CC reading other than 0. Although on occasion I can smell a hint of chlorine. Is it possible I had bad reagents in my test kit?

Thank you for the help!

 

[mknauss]

A loss of 2-4 ppm FC per day is average. Some higher, some lower.

Liquid chlorine needs to be added EVERY DAY during swim season.

Do an Overnight Chlorine Loss Test. CC is one indicator. Not a defining indicator.

 

[demedeirosa]

Thank you. I will give the OCLT a try. So to be clear, I shouldn't be concerned that my CC has never been higher than 0?

 

[mknauss]

I shouldn't be concerned that my CC has never been higher than 0?

No. That is good. It is one indicator of an algae free, healthy pool system. There are two more (pass OCLT and crystal clear water).

 

[demedeirosa]

Thank you!