Very High CYA Levels

[wazu]

Hi All. I have owned my pool (12 x 24 above ground oval) for about 8 years now and never had any real issues until late last year when it seemed like the pool had no chlorine, requiring me to shock the pool more often to maintain my chlorine levels. I just chalked it up to bad luck for the season. I opened my pool this past weekend and had the water tested at a local pool store about 48 hours later. My CYA levels were off the charts (159 ppm). FC was 0.96 and TC was 1.27. PH was 6.3 and Alkalinity was 0. I now presume that the high CYA levels were present last year and were causing the chlorine issues.

In doing some research online (and on this fine forum) I have determined that the Frog Leap Torpedo Pac system I have been using for the past 8 years is the cause of the increased CYA, due to the stabilized chlorine tablets it uses. I realize that I need to drain part of my pool and refill with fresh water to dilute the CYA levels. However, I am not entirely positive on how much water I should drain. Is 25% too much or too little?

Also, I plan on ditching the Frog system in favor of either liquid chlorine or unstabilized chlorine. My understanding is that with liquid chlorine I will need to check the chlorine levels everyday (especially since the pool will be used almost daily during the summer). If I decide to use unstabilized tablets, can I just put them in my skimmer? Also, how often would you test the pool if using these types of tablets?

Thanks in advance of any advice/comments/suggestions.

 

[HermanTX]

Welcome to TFP
The drop in CYA when draining is proportional to amount you drain. A 50% drain will halved the CYA level. You should consider a 75% drain.

Self Testing is a fundamental cornerstone of the TFP program. Suggest you invest in a good test kit such as the TF-100 which you can see Test Kits Compared

Your pH and TA levels are concerning low. Now the TA may be an adjusted TA since you tested at a pool store. Those pucks are lowering those 2 chemicals and that is not good either. TA needs to be above 50ppm and pH in the 7’s

Liquid Chlorine is preferred over any granulated or puck chlorine product. Initially you should test every day but as you start to learn your FC daily loss due to UV and bather load you will back off to every 2-3 days for testing. However you will need to add LC everyday. It is not a weekly dump and ignore process.

Go buy some LC now and put about 1/2 gal in the pool. That will raise FC to just over 5ppm
You may need to add a quart a day to start.

Buy a test kit.

Prepare to drain.

If you do not drain now then I would test Overnight Chlorine Loss Test to see if you have algae. I be surprised if you didn’t have any.

 

[Mdragger88]

Welcome
Sorry we’re meeting this way but we’ll certainly help you get back on track.
+ 1 for everything Herman said &
Here’s a couple more links for you to read
About exchanging water safely without damaging your pool/liner

Draining - Further Reading

www.google.com

& also

How to Chlorinate Your Pool

Before chlorinating your pool, you should know these simple tips. Learn the best way to add chlorine to your pool.

www.google.com

 

[wazu]

Now the TA may be an adjusted TA since you tested at a pool store.

Yes, the report does indicate it was an adjusted TA.

Thanks for all the replies and suggestions. Looks like i have some work head of me.