Super high combined chlorine

[aylad]

I'm glad you found us and posted here. The ways that we describe here DO work! Sometimes it takes a little longer to get where you want to be, but you have to remember that it took about 2 years for your CYA to build up to the point where it broke down into this much ammonia demand, so an overnight fix is just not possible. And at least bleach is much cheaper than lithium!!

It is easy to get frustrated with it, and to doubt yourself, and to just "give it back" to the pool store--but believe me, you'll have this problem fixed soon and enjoy a whole summer in a clean, clear pool, where if you go with the pool store, this is a battle you're gonna fight all summer long. Patience is hard to come by sometimes, but it's a necessary evil!!

We're glad you're here....

Janet

[themaccs]

It is easy to get frustrated with it, and to doubt yourself, and to just "give it back" to the pool store--but believe me, you'll have this problem fixed soon and enjoy a whole summer in a clean, clear pool, where if you go with the pool store, this is a battle you're gonna fight all summer long. Patience is hard to come by sometimes, but it's a necessary evil!!

We're glad you're here....

Janet

Thanks for the encouragement. I guess I'll keep chugging away with the bleach. We're kind of at a stand still today - the good news is I'm able to keep the FC up with a dose every few hours and the CC has been between 0.5 and 1.0 all afternoon (1 drop almost clears the pink, 2 wipes the pink out easily - I would try a 25ml sample but I don't want to use that much reagent). I have managed to keep the FC between 10 and 18 all day (CYA is 40). The bad news: every time I test the results are about the same: losing about 4ppm FC every 2-3 hours, CC staying at between 0.5 and 1.0 ). I feel like this is the same place I was yesterday when the sun was shining, then the CC jumped up to 2.0 when the sun went down. I've used close to 75 gallons of bleach so far. I hope I am getting close! And I know it will be worth it when I have the rest of the summer with a clean clear pool without daily trips to buy more bleach! Thanks again for the encouragement!

[themaccs]

Back to being a little frustrated. I seem to be stuck. Still losing between 5-6ppm FC at night. Stuck at about 1ppm CC. pH - 7.2, TA - 150, CYA - 45-50 (i have a little trouble deciding exactly when I can't see that dot!). I have some time at home again today - is it best to try to keep my FC up at shock level as consistently as I can by doing the every hour check thing again today? Or is the cumulative amount of bleach going to be the same no matter what? Yesterday - partly because of working, partly because of wanting to be able to swim in the evening, we let the FC drift down to 8-10 a couple of times, then dosed it back up last night.

And how soon after I dose the pool can I check to get an accurate reading of my shock level? - I have been calculating what I need using the pool calculator, then testing an hour or so later. I am assuming that I reach shock level when I put the calculated amount of bleach in, but since I am still losing some and not checking till an hour or so later, I have never actually had a test read out at shock level. I am considering my shock level at this point to be close to 20 since my CYA is close to 50. The highest test reading I have had as been 16.

Am I missing something?

[Watermom]

I think you just have to keep at it. As soon as chlorine goes in, it starts to get to work. Yes, to your question about trying to keep at shock level as consistently as you can. The more often you test and add bleach back up to shock level, the faster this is going to get finished. You can't test and dose TOO often. I have no doubt how frustrated you are, but keep hammering it with bleach!

[themaccs]

I think you just have to keep at it. As soon as chlorine goes in, it starts to get to work. Yes, to your question about trying to keep at shock level as consistently as you can. The more often you test and add bleach back up to shock level, the faster this is going to get finished. You can't test and dose TOO often. I have no doubt how frustrated you are, but keep hammering it with bleach!

Thanks for your quick reply! Off to buy some more bleach

[AndyJ]

This must be exactly what I experienced this spring. I had heard of CYA-eating bacteria, but didn't realize this would result in more that simply needing to add stabilizer. I had good to high CYA levels last fall (guessing 50-100) and none this spring. Took 102 gallons of bleach before it would hold FC levels.

I'm now looking for ways to prevent this from happening next winter. I'm guessing some combination of chemical levels during winterizing and earlier spring startup. FC was 0 last fall when closed up, and this spring, it had been ice-free for about a month or so before we opened it.

Pool is a 24k IG with SWG. I live in Minnesota, so it freezes hard from about December through March.

[chem geek]

You can prevent this problem by maintaining an FC level in the pool at all times. Obviously you can't easily add chlorine, let alone mix it well, in a pool that is frozen over, so the next best thing is to wait to close the pool until the water temp gets as cold as possible -- at least below 50ºF. At that point, chlorine will last for quite some time so if you close with a shock level of chlorine or even a higher than normal level, it should last through the season. This is especially the case if you use a pool cover that is opaque to sunlight. If your pool is exposed to the sun, then the chlorine will drop even when the water temperature is cooler.

I know that in my own pool the chlorine loss drops to less than 1 ppm FC per week when the water gets to around 50ºF and I suspect that when near freezing the chlorine loss rate is less than half that. However, I have a mostly opaque safety cover.

You should then open the pool before the water warms up, so definitely before it gets above 50ºF.

There are other ways to avoid the problem that involve the use of supplemental products (PolyQuat 60, for example) at extra cost, but the above method using chlorine alone is simple and inexpensive.

[AndyJ]

Thanks, chem_geek. I read the fall closing sticky thread and it said to maintain FC all winter. The author mentioned checking the chlorine periodically throughout the winter and adding it as necessary, but as you mentioned, I couldn't see how that is possible if my pool is frozen solid. I see now that I can just raise it to a high level to last the winter. I do have an opaque auto cover, so that will help prevent FC loss.

However, I also saw mentioned that FC should not be too high, or it might damage my cover, since it will not vent excess chlorine fumes well. I'm guessing a level in the 15 ppm range might be a good medium upon shutting the pump down, say when the water temp is about 40-45.

I did see PolyQuat mentioned as well, so I may give that a try. With your advice, I'm hopeful my situation will be much better next spring. Thanks again.