No Chlorine?

[Watermom]

Stick with just using bleach for now. Some of the pool chemical companies are making blends with unwanted ingredients in their products. We call them voodoo mystery mixes. Post your overnight results in the morning.

[MartyW]

Retested with fresh R0013 - same results. Will add 5 gallons of 12% pool bleach tonight. May not be able to post results until tommorow evening.

[Watermom]

5 gallons of 12% with a CYA of 50-60 in an 18K gallon pool would add about 33ppm of chlorine. Too much. Only add 3 of the gallons. That should add about 20ppm which is high enough. Test about an hour after you add it this evening and then test again within two hours of sunrise in the morning. What you need to find out is if you are losing more than 1ppm overnight. That information is an important piece of the puzzle.

[MartyW]

I had already put 5 gallons in around 9:30 pm before I saw your last post. At 10:30 pm I read FC @ 17ppm and CC @ 4ppm. At 6:30 am I read FC @ 1ppm and CC @ 1ppm. This evening was FC @ 0 and CC @ 0.5ppm. I'm baffled! Thanks for your help. Marty

[aylad]

Those test results say that there is something in the water that is consuming your chlorine, so the next step is to take it to shock level (chlorine 20 ppm) and hold it there until you can go overnight, testing just like you did, but not losing more than 1 ppm of chlorine in that time.

If you used trichlor pucks last year, what was your CYA when you closed? I'm betting it was high, and the fact that you had none on opening means it degraded over the winter. One of the possible byproducts that it sometimes will degrade to is ammonia, which creates a very high chlorine demand, but one that must be overcome with lots of chlorine before you'll be able to hold a chlorine level overnight. We've seen a lot of that happening this year, unfortunately.

Janet

[Watermom]

Jan,
I started replying and was pretty much writing the same thing you wrote above but deleted mine. The puzzling thing about this one is that even if she did have CYA bio-degradation over the winter, why doesn't she have a high CC reading? I've asked Ben to take a look at this thread.

[PoolDoc]

The puzzling thing about this one is that even if she did have CYA bio-degradation over the winter, why doesn't she have a high CC reading?

She *has* had transient high CC levels. The thing you have to remember is that breakpoint chlorination -- so long taught in the pool industry -- actually WORKS, when the chloramines come from simple ammonia chlorine mixes. So, 'shocking' to eliminate chloramines can potentially do just that.

[aylad]

I had already put 5 gallons in around 9:30 pm before I saw your last post. At 10:30 pm I read FC @ 17ppm and CC @ 4ppm. At 6:30 am I read FC @ 1ppm and CC @ 1ppm. This evening was FC @ 0 and CC @ 0.5ppm.

With a FC of 17, and a CC almost 25% of that, something's eating it up. May or may not be ammonia, but either way the pool still needs shocking.

Edit: Pooldoc's post button works faster than mine tonight!