Is draining the ONLY way to lower CYA?

[jantzengomez]

Hello everyone. Many of my google searches kept leading me to this site, where the forum has been very helpful. Feeling very convinced, two months ago I switched over to TFPC and have been content with the results.

At the beginning of the conversion (once I received my test kit), my CYA was probably around 90 and I tested and maintained the pool using Pool Math. I was pleasantly surprised when ~3 weeks later the CYA was about 45. Then about another month goes by and I noticed that I could not visually see that layer of chlorine at the bottom of the Liquidator. Tested and CYA was ~20. I've read all over this site that to lower CYA to acceptable levels was to drain.

*I never did drain to lower CYA*

The question: So did CYA drop because I stopped using the tablets and the normal evaporation/pool filling over time?

Thank you in advance.

 

[jblizzle]

Welcome to TFP!!!

CYA does not evaporate. A significant drop like that may mean you have a leak. Do you have an auto-fill on the pool that could be masking a leak?

Or have you been getting a LOT more rain than I got in the NW side?
Or have you been doing massive baskwashes?

 

[Billrector]

The only way I see that you could get your CYA that low would be to introduce a lot of new water. As Jantzengomez said, that probably indicates a leak unless you can think of something else that caused a whole lot of new water to be added.

 

[tim5055]

Or, if your pool water eliminates CYA we need to bottle and sell it

Seriously, as has been said. Water replacement is the only way it really could have gone down that much.

 

[rodog123]

My CYA is holding steady at 30. Tested on my own and took to the dreaded Leslie's (just to compare) for testing ~ in the same ballpark.

We get significant splashout from 3-5 kids getting in and out of the pool and with much rain here in Houston I believe this has kept my CYA down.
I've been using pucks for 5 months no problems as of yet.....

 

[jantzengomez]

I'm glad you responded jblizzle since I knew we are in the same city. I did deal with a leak back in April/May and determined it was a crack between the cool deck and space the auto fill comes in. I was fairly certain after my repair that I solved the leak. I would say the monsoon rain this season on the westside has been fair, not like the eastside of town.

*This pool is at a rental house and when they received their 1st water bill it was over $200. This is what lead to the investigation. They wanted a credit so they provided the next 3 months of bills and each month it was lower. From $220 to $92 to $79 to $68. April thru July. I don't believe I have a water leak but I will do the bucket test again.

I did a major sand filter cleaning a couple months ago during the conversion and the CYA was then at 45 and I was happy. Perhaps there a problem with my testing? I know how to follow directions that came with the test kit.

 

[Tink9305]

It sure would be nice if something other than a water change lowered CYA ) On the East side here but the rain didn't help my CYA

 

[ewkearns]

I found a reference on the Internet to "Peroxolyte", which is supposed to have some magical properties associated with lowering CYA.

Any thoughts?

 

[duraleigh]

Any thoughts?

Disregard it. Draining remains the only practical way.

 

[tim5055]

I found a reference on the Internet to "Peroxolyte", which is supposed to have some magical properties associated with lowering CYA.

Any thoughts?

it has been discussed a few times over the years. Here is chem geek's comment about the CYA claim from 2011

Because the product is a combination of a persulfate with cobalt ion and that this is known to produce very strong oxidation, it is possible that this can oxidize Cyanuric Acid (CYA). So their claim is at least plausible. However, such a strong oxidizer may very well oxidize swimsuits, skin, hair and pool equipment much faster so that would be a concern. As something to use when shocking or for Crypto or when fast oxidation is needed, it sounds reasonable, but for continual disinfection it might be too strong an oxidizer. Basically, one wants something that kills pathogens quickly, but isn't so strong an oxidizer as to affect things you don't want oxidized. This is very difficult to do, though many oxidizers, including chlorine and MPS, are rather selective. Chlorine with CYA seems to give a reasonable balance, though of course it has disinfection by-products.

Anyone is welcome to try this by buying a small amount of the product and doing bucket tests for experiments. That's how we ultimately determine the validity of claims.

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