CYA out of control, closing in a couple weeks

[ChewBiscuit]

Ok, I finally got my TF-100 kit.

My first set of readings:

FC - 1 (used basic kit for now)
Ph - 7.5
TA - 100
CH - 270
CYA - 110 (was about a 1/16 in. below the 100 mark, so recorded this as 110)

So I'm low on chlorine, slightly high on TA.

But if I understand correctly the CYA is out of control. This pool had been used for years before I moved in with tablets, so I'm not terribly surprised. (I've been doing BBB) I have a little bit of algae, and I noticed my chlorine doesn't seem to be killing it. I wondered if this was going to be the problem. (oddly enough, I had gotten a reading from the pool store a while ago and they thought their reading of 125 was find and dandy, no problem)

So, I had hoped to SLAM the pool before closing in a couple weeks to get rid of the algae. But I'm not sure how to do that with this high CYA. On the other hand, according to the calculator, I'd have to drain over half the pool in order to get it down.

What would you recommend? Should I drain way low for closing so snow and rain can help refill it, hopefully starting the spring with a lower CYA even if the water's not sparkling clean and may have algae when I lift the cover?

Off topic, but when the CH test water turned blue, there were what looked like little red dots swirling around in it. I wasn't sure if that was when I should stop the test and record the results, but I did. Was that the right way to do it?

Any help and advice, as always, is greatly appreciated.

 

[duraleigh]

It's a bit of a toss up but I think I would leave it 'til next Spring and then first test your CYA and drain/refill to get it right if necessary. Then SLAM.

 

[Leebo]

Add another vote for leave until spring.

 

[ChewBiscuit]

Thanks, sounds good. Since the water gets drained a little anyway for closing, would there be any harm to my liner or anything if I drop it an extra foot or 2?

 

[JFB]

+1 for spring, but if you are seeing algae right now, I think SLAMming before closing would do your pool some good and it would be one less problem to deal with come the spring...

 

[duraleigh]

would there be any harm to my liner or anything if I drop it an extra foot or 2?

We typically suggest leaving at least one foot of water in the shallow end to keep the liner in place. I see no real advantage in draining it further than normal closing.

 

[ChewBiscuit]

+1 for spring, but if you are seeing algae right now, I think SLAMming before closing would do your pool some good and it would be one less problem to deal with come the spring...

Ok, so it's safe for my equipment and liner to add the amount of chlorine necessary to account for the CYA in my pool?

Should I add it a couple gallons of bleach at a time?

 

[ChewBiscuit]

would there be any harm to my liner or anything if I drop it an extra foot or 2?

We typically suggest leaving at least one foot of water in the shallow end to keep the liner in place. I see no real advantage in draining it further than normal closing.

Ok, I thought draining more would help lower the cya more. Still learning.

Thanks for input everyone.

 

[zea3]

would there be any harm to my liner or anything if I drop it an extra foot or 2?

We typically suggest leaving at least one foot of water in the shallow end to keep the liner in place. I see no real advantage in draining it further than normal closing.

Ok, I thought draining more would help lower the cya more. Still learning.

Thanks for input everyone.

Draining more would lower more CYA, but if you are not going to slam until spring you may as well wait until then to adjust the CYA levels. Sometimes a green pool left over winter will develop a bacteria that breaks down the CYA and leaves an ammonia by product in the water. If that happens you would not need to drain any more water and the slam process takes care of the ammonia as well as the algae.

 

[JFB]

Ok, so it's safe for my equipment and liner to add the amount of chlorine necessary to account for the CYA in my pool?
Should I add it a couple gallons of bleach at a time?

I'll let the other experts weigh in on safe levels for equipment. I am not an expert on that. I had my pool at 25 FC in the last couple days as I was SLAMming, and my CYA is 40 or less. Equipment is still working. I'll tell you in 3 years if that was a good move!!

Read the comments at the bottom of page pool-school/chlorine_cya_chart_shock It says you don't need to bring it up all the way to shock at high CYA, but it will take more time to shock...

Spring for everything is starting to sound a little better after reading everyone else's comments...