AG Pool Closing with High CYA

Hello. I have read the sticky thread on Closing AG Pools and am somewhat familiar with the "Best Guess Chart" but I still could use a little hand-holding in closing my pool.

I started out the season using the "Relax" system that the pool store recommended. It consists of adding some magic dust to the skimmer every week and placing some "pucks" in the skimmer every month or so. Although that system actually worked well at keeping the water clean, it is expensive and after reading on this forum, I moved away from that system and began using just bleach and Borax.

My CYA levels have been high since I started testing using the Taylor kit this year (over 100 ppm… I began using the Taylor at the same time I started using bleach and Borax). So today my levels are:

FC=1.5; CC=0; pH=7.3; TA=50; CH=30; CYA>100

I plan to use a winter cover. I am afraid to bring my chlorine up to the shock levels suggested in the Best Guess chart. Also, I have closed the pool for three seasons by just adding one or two 1-lb bags of shock and the water has always been clear when I opened. Since I wasn't really testing back then, I can't say what the chlorine levels really were.

Should I really increase Chlorine levels to around 25 ppm? Any other suggestions based on my levels?

Thank you all for your excellent support!

Yes. With a CYA that high, the high chlorine levels won't hurt a thing. It is no different than having a pool with no CYA and a chlorine of 1-3ppm. I would also suggest bumping your pH up to around 7.8 or 7.9 to give it some wiggle room over the winter without dropping below 7.0. You'll also probably want to raise your TA up to around 90-100ish which will help keep your pH more stable.

Thanks Watermom. How should I raise TA and do you think I need polyquat?

Use some baking soda to raise TA. You can use some polyquat if you want. Some do. (I don't in my pool but CarlD does.) It certainly won't hurt anything if you decide to.

Just remember that Polyquat lowers FC especially if you add a large amount, like a quart.

Thanks Carl. So since I do not have an algae problem and since I plan to use a winter cover, should I bring chlorine to maintenance, just above maintenance, or shock levels? I assume from both your and Watermom's sticky posts on pool closing that it needs to be closer to maintenance level when the cover goes on so as not to damage the cover?

Whoops. Think your questions got missed. Did you close yet?

No. I am still waiting. I just want to know whether i need to chlorinate to shock level to close, even if I do not have an algae problem. Thanks!

.
I think Watermom actually answered that question. It might have gotten missed with the TA recommendation. You asked:

Quote:

---

Originally Posted by bottomcat

Should I really increase Chlorine levels to around 25 ppm?

---

Her reply was:

Quote:

---

Originally Posted by Watermom

Yes. With a CYA that high, the high chlorine levels won't hurt a thing. It is no different than having a pool with no CYA and a chlorine of 1-3ppm. I would also suggest bumping your pH up to around 7.8 or 7.9 to give it some wiggle room over the winter without dropping below 7.0.

---

(How you didn't have algae with a FC that low, I don't know! You have some luck!)

Did you have any other questions?

I guess I'm all set. Since I wasn't clear in my OP that I was not trying to clear up algae, and since Watermom's sticky is addressing algae, I wanted to make sure I had it right. I was looking for clarification between "it won't hurt" and "it is recommended." I'll just bring it up to around 25ppm (496 oz of 8.25% bleach!) and be done with it. Thanks all.