Free Chlorine Creeping Up

Areobee

Member
May 29, 2019
5
West Palm Beach, FL
So over the past 3-4 weeks I have noticed that my free chlorine has been creeping up. It WAS about 6 with a CYA of about 50. My water is crystal clear (Thanks to this site). I have been running solo for about 7 months now (Fired pool guy). Anyway, the chlorine has been increasing about 1ppm a week... Today I tested and the FC is at 10 with the CYA at 40.

I live in South Florida,
New Salt pool w/spa,
plaster,
pool was finished in January of 2019.
Salt Gen. was set to 80% since construction.

My thinking is to not overreact but since its been rainy and cloudy for a few weeks and the weather has started to cool down a bit and the pool is probably established I should back the salt gen. down to 60%

Also, We have not been swimming much lately... maybe 2 times a week for the past 3 weeks.

I don't think having high chlorine is a terrible thing but still being a novice, I don't want to be blindsided by something I don't know about.

It just may be that I am not losing as much chlorine as I was in the beginning.

Of course this is just a gut feeling...

Any thoughts would be appreciated...

Thank You
Rob
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,812
Northern NJ
My thinking is to not overreact but since its been rainy and cloudy for a few weeks and the weather has started to cool down a bit and the pool is probably established I should back the salt gen. down to 60%
Correct. Shorter days and lower sun angle has less UV rays to burn off FC during the day this time of year. You need to make adjustments to your SWG as the seasons change.

I don't think having high chlorine is a terrible thing but still being a novice, I don't want to be blindsided by something I don't know about.
CYA 40 is low for a SWG. Our recommendations are CYA of 60-80 for a SWG pool. Although it can work this time of year.

Any FC level up to the SLAM FC leve4l on the Chlorine / CYA Chart - Trouble Free Pool is safe to swim in. For CYA 40 that is 16.

If you raise your CYA to 60 then your FC target would be 4 and FC can rise up to 24 and be safe to swim in. So you have lot's of headroom to make adjustments to your SWG output.
 

Fuldo

Silver Supporter
Nov 23, 2017
172
Port Orange, FL
How is your system set up? Is the SWG on a timer and if so how long does it run each day? Your setting of 80% with that SWG seems about right for summer if it's run for maybe 8 hours or so per day. That SWG has a rather low output compared to most SWGs rated for 40K. Although my RJ30 is rated for the same size pool it's rated output is about 50% higher than yours. (1.5# compared to 0.95# per day).

As Allen mentioned TFP normally suggests a CYA of 60-80 for SWG systems. Your pool however is in a screened enclosure, as is mine, and that greatly reduces sun exposure and chlorine demand. I've found that CYA of 30-50 works great for my Florida pool and prefer to run it in that range after being bitten by excessive CYA in the past. My chlorine demand is rather low with CYA 30-50 and if an algae problem is encountered it's far easier to SLAM the pool than if the CYA was much higher. Then again, I haven't had an algae problem or any significant water problem since ditching pucks, draining and rebalancing the water.

Although you have a VSP, you may still find you can save some money by reducing pump run time in cooler weather and adjusting SWG output accordingly.