High chlorine demand

[dojiboy]

Is high chlorine demand an indication that I need to shock my pool?

Every since switching to BBB a week ago my water is crystal clear and I don't accumulate nearly as much "junk" at the bottom of the pool. However, my chlorine demand is 4-5ppm per day. Not sure if this is within normal limits, or if I should think about shocking. CC is less than .5ppm, the water is clear and OCLT is 1-1.5ppm.

Thanks!

Doji

 

[Beamup]

OCLT more than 1 ppm suggests a need to shock, as it demonstrates that there are organics in the pool which the chlorine is fighting.

 

[duraleigh]

You are calling it high chlorine demand but seem to imply that it is nothing out of the ordinary and has been going on for some time. Help us understand if it's a recent trend or not.

Secondly, you need to tell us your CYA which is all-important to chlorine consumption.

Normally, I would suggest shocking also but your OCLT results are VERY borderline so the answers to the above questions give us a much clearer picture.

 

[dojiboy]

Sorry. I guess that's the point of the question. Not sure what high is.

CYA is 60. I've been raising FC to 9 at night, it's 7.5-8.0ish in the morning and back at 4-5 by evening.

Only started BBB about a week ago so no idea what was going on before that.

I've probably never technically shocked the pool. Just followed the pool store instructions of dumping 2.5 gals of chlorine per week.

The water has never looked better.

Thanks!

 

[duraleigh]

I'm sorry I missed that "one week" in your first post. Based on that and your CYA value, I would shock the pool.

Once you complete the process, I think your FC consumption will drop noticeably.