High CYA: An Upside?

[cheshamjim]

High CYA content mitigates chlorine's sanitizing properties, right? At the same time, does high CYA mitigate chlorine's negatives, e.g., if I shock a low CYA pool with 25 ppm chlorine, I might damage a vinyl liner or swim suits. Would I face the same kind of risks shocking to 25 ppm when my CYA content is well in excess of 100?

-Jim

[Watermom]

In a nutshell, no. Take a look at the "best guess" table in the sticky at the top of this forum. It will show you how high you need to shock based on your cya level.

[aylad]

One positive about high CYA (mine is in the 80-90 range) is that, even though you have to maintain higher minimum chlorine levels, it takes much longer for the Cl to be consumed by the sun and the pool.

Janet

[joliecharlie]

On the old forum someone had a vacation home with pool that they only visited on weekends. Ben's suggestion was to raise CYA significantly, then they could shock before they left it, and Chlorine would drift down during the week...Anybody remember that post?

That's how I lived with my pool for 2 years as the CYA was well over 100 and partial drain was out of the question.

It has finally dropped to 50 naturally with rain, backwash, etc. I liked my pool care better with it higher and I am now carefully raising CYA with pucks.

[cheshamjim]

In a nutshell, no. Take a look at the "best guess" table in the sticky at the top of this forum. It will show you how high you need to shock based on your cya level. I didn't do a very good job of asking my question. I do use the Best Guess table to determine where I should keep my chlorine level. I'm just curious whether higher chlorine content required by high CYA levels is as potentially damaging as high chlorine content would be in a low CYA pool. Or does the high CYA somehow cancel out the damaging effects of high chlorine?

Watermom, Janet, and Charlie, you have probably answered my question already, but you are dealing with a pretty dense fellow here. Maybe you would consider taking another shot at an answer.

-Jim

[joliecharlie]

Others can answer more technically I feel sure. If you are concerned with fading, I haven't noticed any with swim wear, my liner is about 4 years old and has some slight fading but I would guess that to be normal, we also keep our pool open year round.

[prh129]

Actually I think there was a mistake in Watermom's response - I think she meant "it will show you how high to shock based on your CYA level" not chlorine level.

I believe that the higher CYA level will bind up more of the free chlorine so a 25ppm chlorine level with CYA of 100 should not damage a liner as 25 ppm chlorine with 0 CYA would. I'm not 100% sure of that though but it makes sense - if you have to have a higher Cl level to keep things sanitary then the amount required to cause fading would have to be higher as well.

Peter

EDIT BY WATERMOM -- Peter, you are correct. I did mean cya level. I corrected my post above. Thanks for catching it.

[cheshamjim]

If you are concerned with fading, I haven't noticed any with swim wear, my liner is about 4 years old and has some slight fading but I would guess that to be normal, we also keep our pool open year round.Fading of swim suits and liner is precisely what I am concerned about. Your experience over time with high chlorine is a great insight and I thank you for sharing. I'd still like to hear an expert opinion, though.

-Jim

[Watermom]

I'm just curious whether higher chlorine content required by high CYA levels is as potentially damaging as high chlorine content would be in a low CYA pool. Or does the high CYA somehow cancel out the damaging effects of high chlorine?

-Jim

Jim - You are correct. High chlorine content with high cya is not as potentially damaging as high chlorine with low cya. The way you worded it is exactly right. Hope this helps.

[cheshamjim]

Thanks Mom...

[Watermom]

You're welcome! :)