Not all CC created equally?

[ryguy76]

My water is nearing the end of its life cycle, (based on my current TDS reading being about 1300ppm higher than it was at startup). What I’ve noticed with this first fill using the Dichlor/Bleach method is that initially I had some expected CC immediately after a soak (~0.4ppm) which was pretty much gone the next day as anticipated. But... over time, a base CC level slowly creeped up as the weeks passed and it stopped going back to 0ppm after dosing with liquid chlorine. I’m almost 4 months in on this fill and the CC stays around 0.6ppm and won’t drop any lower even with a superchlorination above 12ppm or a shock and sustain of a few days. I’ve even kept the cover off on a bright sunny day for hours and that ate up my FC but didn’t drop my CC below 0.6ppm.

Only thing that makes sense to me is that the CC that’s registering on my K2006 kit isn’t the same as CC that’s able to be broken apart with FC greater than Breakpoint. Is this normal and able to be explained?

 

[PoolStored]

I'm sorry you haven't had a response. I no nothing about spas. Maybe this will help. I don't think there are different types of CCs.

I am seeing CC at 3 in my spa

I have been trying to get the TA down in the spa since the Ph was rising to 8.2 when aeration was in use. The TA had gone to 110 so i lowered it to 50 with dry acid and that seemed to correct the issue. I also needed to add stabalizer to the tub as it had slipped to 18 from adding water...

www.troublefreepool.com

 

[ryguy76]

I'm sorry you haven't had a response. I no nothing about spas. Maybe this will help. I don't think there are different types of CCs.

I am seeing CC at 3 in my spa

I have been trying to get the TA down in the spa since the Ph was rising to 8.2 when aeration was in use. The TA had gone to 110 so i lowered it to 50 with dry acid and that seemed to correct the issue. I also needed to add stabalizer to the tub as it had slipped to 18 from adding water...

www.troublefreepool.com

Hey, no worries. I eventually found some older threads where Combined Chlorine was discussed and there is volatile and non-volatile CC’S as well as Organic and Non-Organic CC’s. The organic CC’s appear to be more challenging to get rid of and don’t respond to chlorinated shocks in the same way. Others had said they noticed a slow creep of CC‘s that weren’t lowered by shocking and it was speculated by ChemGeek that they were organic and non-volatile and likely not an issue as the non-volatile variety don‘t cause irritation to bathers. So sounds like what I‘m seeing isn’t unheard of and might just be a decent measure for a water change when that unresponsive CC level gets too high.

 

[JoyfulNoise]

Hey, no worries. I eventually found some older threads where Combined Chlorine was discussed and there is volatile and non-volatile CC’S as well as Organic and Non-Organic CC’s. The organic CC’s appear to be more challenging to get rid of and don’t respond to chlorinated shocks in the same way. Others had said they noticed a slow creep of CC‘s that weren’t lowered by shocking and it was speculated by ChemGeek that they were organic and non-volatile and likely not an issue as the non-volatile variety don‘t cause irritation to bathers. So sounds like what I‘m seeing isn’t unheard of and might just be a decent measure for a water change when that unresponsive CC level gets too high.

Yup. Persistent CCs build up over time. No getting around it. TFP suggests dumping the tub every 3 months at least and doing annual purges with Ahhsome to ensure clean plumbing.