Pool Opened: High CyA (147 ppm) and FAC (15 PPM)

dobenshain said:

I lowered our 22K gallon pool by about 1 foot on saturday, and refilled with tap water. I also purchased a CyA remover from Leslie's. It's a pouch that sits in your filter basket and adsorbs the CyA out of your water (supposedly 10 ppm / week).

Any recommendations on bringing the FAC down? We stopped adding pucks a week ago because of the high chlorine.

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It’s only high chlorine if you had low or no CYA. But at your CYA level it’s more likely your chlorine isn’t high enough.

That was the biggest lie pool stores ever fed us: that no matter what, any FC over 1-3ppm was extremely dangerous. The store associates had no understanding of the relationship between CYA and chlorine. Besides - if you keep it no higher than 3ppm you are always needing more, and more often, and that makes them money. At lower chlorine levels you are flirting on the edge of disaster on a daily basis if not hourly.

Better to have a higher CYA nearer 60-70 and keep chlorine higher to give more peace of mind and longer lasting chlorine. I can understand bringing CYA down from 147 because your level of chlorine is probably not high enough, but I only know of one way to quickly lower it and that is exchanging out the water. Careful about gimmicky pool store products. I’m not saying there can’t be anything new out there to lower it, I just never heard of it before this post and I’d be skeptical given the industry who is selling it.

Texas Splash said:

I have to say, I'm not familiar with any such product that will remove CYA. What about you JD

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Well, this is a first for me, but I see it on their website. GreenStory Global Cyanuric Acid Remover. $80 for a little filter thing you put in the skimmer. Just walking in to it I'm feeling all sorts of snake oil vibes. Such as the claim that it removes 10 ppm per week with no explanation of how it does so with regularity regardless of CYA level nor is there anything I see indicating how much CYA it will filter out in total.

I found the website and SDS, but I think I'll start a thread about it in the Deep End so as not to take over OP's thread talking about it. I'm very skeptical, but there are much better chemists than I who I'd like to hear from.

EDIT: Here is that thread: GreenStory Global Cyanuric Acid

Yes 15ppm is safe to swim in if your CYA is that high. We follow this chart below to always keep ours in the target range, (not minimum because … “edge of disaster,) and refer to it for the proper slam levels too. It only goes to a CYA of 100 though so you really need to rely on PoolMath calculations for your target levels, (will PoolMath go that high?)

Anyway so long as your CYA is high you should carry a higher FC.