Increasing CYA using chlorine tablets

[WaterwayHaven]

We’ve had a lot of rain and my CYA is outside the ideal range at 35. I would like to increase it to at least 40 since my pool gets full sun all day and wanted to use Chlorine tabs to do it. When we bought the house there was a bucket of Clorox Florida Blue that I was considering using but I see it has some copper and that’s giving me pause. This is not meant to be my sanitizing method; I use liquid chlorine for that but rather to complement it while maintaining CYA at the ideal level. Can I use these or should I avoid any product with any traces of metal in it?

 

[Rancho Cost-a-Lotta]

Copper in the water is not a good thing. It can lead to staining and green hair. Avoid the use of Clorox Blue products.

Copper in Pool Water - Further Reading

www.troublefreepool.com

 

[SecoSteve]

So, these tabs came with the house/pool. If it is an open container, you have to expect the previous owner used them in your pool. Do you see any staining of the plaster? I can't imagine minimal use of a couple tablets will cause any issues in your pool, as long as you don't put them in the skimmer. Do you have a floater you can use?

Your other options are to put them in the trash and end up in a landfill, which is not good. Or, keep them and not use them, which is taking up space and chemicals just sitting around which is not good either.

I say go ahead and use them sparingly, but I am not an expert.

 

[V___25]

For the CYA test, you round up to the number - you can't interpret between the lines so your CYA would be measured at 40.
The spacing between the lines on CYA viewing tubes varies and is not linear. With all the uncertainties in this test don't bother trying to interpolate between the lines on the test tube, always round up to the previous line.

If you want your CYA at 40, you are fine. If you want to raise it, use the powdered or liquid stabilizer and avoid those pucks.

Beware of Metals Added to Algaecides or Trichlor​

Metals can also be inadvertently added to the pool water by pool owners. Metal ions were often found in many different commercially available algaecides but, more recently, have been added to many types of “multipurpose” chlorine tablets.

These tablets often contain only partial amounts of TriChlor (a chlorine source) but often have sizable fractions of baking soda, metal salts (like copper citrate or copper sulfate) and weak clarifiers in them. Pool owners are fooled in paying more for less active sanitizer, chlorine.

The key word to look for and avoid is anything that has the work "Blue" in it. That is market speak for copper. These products are something you want to avoid.

 

[WaterwayHaven]

Thank you everyone! I will not use the tabs and make sure that any future pucks I may buy do not have any metals. Do you have any brands you recommend for when we go on vacation?

 

[Chief2505]

If 1# of tablets raise the CYA 6-7 PPM in 10,000 gallons how much does that same amount raise the CYA in 35,000 gallons? 21-25 PPM or a total of 5-6 PPM?

 

[mknauss]

If 1# of tablets raise the CYA 6-7 PPM in 10,000 gallons how much does that same amount raise the CYA in 35,000 gallons? 21-25 PPM or a total of 5-6 PPM?

1.9 ppm
Use Effect of Adding Chemical -- PoolMath