New to BBB / Need to understand Chlorine loss

Dennis T

Member
Jun 12, 2012
13
Columbia, SC
Last Night's readings were

FC 4
CC 1.5
PH 7.45
TA 160
CH 180

I added 73 oz of bleach to get FC level to 5

Tonight's Readings

FC 1
CC .5
PH 7.4
TA 170
CH 180
CYA 50

It was sunny and mid 90's today. Here in Columbia we have full sun most days. Is this level of FC loss in a 24 hour period normal for the climate we live in? Thanks, Dennis
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
The "norm" (if there is such a thing) seems to be 2-4ppm per day.

Looks like you may be a little on the high side. Doing an OCLT can confirm if there is anything living in the pool making your use higher.

EDIT: Oh yeah, did not see the CC ... definitely do the OCLT
 

Dennis T

Member
Jun 12, 2012
13
Columbia, SC
Thanks fo rthe reply

6/18 - FC .6 / CC .8 added 247 oz bleach

6/20 - FC 4 / CC 1.5 added 73 oz bleach

6/22 - FC 1 / CC .5 Wondering what to do

I'm sorry but I do not know what OCLT is. Thanks, Dennis
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
you have to test after dark at night and then before the sun comes up in the morning to do the test accurately.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone ;)
 

Smykowski

TFP Expert
LifeTime Supporter
I'd shock it, but not because of the overnight loss. The loss was less than 1, and I think that's even within the error of the test. I'd shock it because you're letting your FC get too low. With a CYA of 50, you should never let it get below 4, and preferably be between 6 and 8.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
You are letting the FC get way too low. You should be adding daily to stay above a FC of 4ppm at all times.

I would raise the FC up to shock level once and let it drift down. Then redo the OCLT tonight to see if you need to continue the shock process.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone ;)
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
bottom line is that 4 is a minimum and if you are losing 4 ppm per day then you need to be dosing up to 8.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone ;)