CC creeping higher

[dnh]

Hi, I had great luck this summer keeping the pool clear and balanced. But since it has turned cooler here in Dallas, TX, the CC has rarely been at zero. It has been 0.5ppm or less (just barely pinkish color) We went out of town for the weekend, so I put in some extra chlorine. The CYA is around 30, it is about a 26,000 gallon pool. The FC tested this morning at about 5, but the CC is 1. Why is it going higher, the pool looks clear? We did have our back fence re-stained last week, they did cover the pool, and I had the pump turned off for a day. I normally have the pump running for about 5 hours a day.
I brushed the pool down several times last week, do I need to do more, or just slam the pool?
Thank you

Don

 

[JamesW]

As the water gets colder, the test reactions are slower. Try waiting longer between drops and swirl fast. A speedstir can help. If that doesn't help, bump up the fc to 10 and do an overnight chlorine loss test. If there is more than 1 ppm fc lost overnight or more than 1 ppm cc, do a Slam. Brush the pool today and leave the pump on overnight.

 

[Kiss4aFrog]

If you have a light you might want to pull it and check out the niche it's in. Also the inside of the skimmers and the bottom of the rungs if you have a ladder. These are places algae can hide in and be very hard for the chlorine to reach properly.

 

[dnh]

I put the FC up to 10.5, the CC was almost zero (just slightly color after adding 5 drops). Ran the pump all night and rechecked first thing this morning, FC still took 21 drops (10.5) and CC was 0.5. I slowed down the drops and stirred more. So I think I am OK. Ill keep brushing things down the next few days, and maybe test at the end of the day instead of in the morning.

 

[Richard320]

If you got windblown stain or a bunch of dirt or leaves in the pool, that could account for the CC climbing as well.

Remember, bleach is an oxidizer. It's like combustion without the flame. CC is soot and smoke, sort of half-burned organics. When you're checking lights and stairs, also make sure the skimmer and pump strainer are also clean. Just because stuff isn't in the pool doesn't mean it isn't in the same water.