Opened Pool Yesterday with Question

Yesterday I opened the pool (took off the cover) of a IG 22000 gallon 37' Gunite pool in Round Rock, Texas. I waited until my Live Oak trees stopped their daily dumping as they do every spring.

The water was crystal clear with no algae. This was nice to see, and a good reward for keeping up the bleach and mauratic acid treatments over the winter, about 3 large jugs Bleach per month, and 1/2 gallon acid per month to keep the PH down. I also ran my pump on low speed 4 hours per day.

I dusted off my PS233 test kit (stored in dark place in my house), and here are the numbers:

FC 1.5
CC .5
TC 1.5
PH 7.8
Alk 160
Cal 220
Cya 0
Temp 74

After this test I added another large jug of bleach, and 1/2 gallon of acid....

Last Fall before shutting to pool down I had:

FC 4.5
CC 1
TC 5
PH 7.5
Alk 150
Cal 300
Cya 50
Temp 76

My question is, "Where did my CYA go, or is my test kit result inaccurate from being old?" I think I will see Marty at the pool store with a sample before I decide to add CYA. What needs to be replaced in the PS233 kit year to year?

Thanks,
Jim

There is a phenomenon that some of the posters (but not all) on this forum experience that is just what you described--varying levels of CYA at closing, with none on opening. Most of the time the ones that lose the CYA have algae, and the algae will break CYA down over a winter season. Other than an algae outbreak, I really can't explain why it happens, but it does. It doesn't happen in my pool, (but then again mine stays open year-round), but one of the other moderators, Watermom, has it happen in hers. Weird, huh?

If your test kit has been stored in a dark, cool place, the only thing I would worry about replacing is the dpd powder, and even then only it's clumped up or dark gray in color. The rest of the reagents should be fine.

Janet

As Jan said, Every year I open to no cya - even though there is always some when I close. I never have an algae bloom, so I have no idea where it goes. I just add a startup dose each spring, and then I'm good to go for the summer. No big deal.

Thanks for the replies. I guess I'll add some CYA with the goal of 15 ppm, and see how long that takes to show, maybe a week or so, and then eek it up to 30-40 ppm SLOWLY.

Last year at this time my CYA was >> 100 ppm after I bought this house & pool combo. I found this site by chance, and started following the recommendations including a 50% water drain / fill. The former owner used Tri-Chlor pucks. In fact I still have a bucket of those dudes. Maybe this is a good time to use these up to provide chlorination + stabilizer, and then cut back and replace with bleach once my CYA comes up where I want it. What-da-ya-think?

Jim

Yup, if you're gonna raise your stabilizer, you might as well use the pucks, as long as your pH doesn't nose-dive, until you get it where you want it.

Janet