Safe swimming levels for FC?

[steveg_nh]

I was wondering what the safe swimming levels are for free chlorine. I was looking at the HTH website regarding a question I had for the stabilizer and I read a comment that swimming above 4 ppm for free coloring posed a risk to your body.

I've been through all the pool school articles a couple of times and I can't call seeing anything that specified book the safe ranges were for any of the items that we balance. For example I was shooting to have my pool, which is a saltwater pool, at a CYA reading of about 60 or 70. That puts my maximum free Chlorine at 4 to 5. Both above the limit that comment referred to.

Any insights on this when running a trouble-free pool would be much appreciated. Thanks!

 

[JasonLion]

Our rule of thumb is that anything below shock level is fine.

The 4 ppm rule applies to pools that don't use CYA at all. When you are using CYA, even at shock level, the active chlorine level is way way below the level it is in an indoor pool without CYA and an FC level of 4.

 

[steveg_nh]

Thanks. Why would a large public pool not use stabilizer? I thought that was one of the cornerstones of proper water care in general?

 

[JasonLion]

The pool industry is both fairly conservative and driven by commercial interests that have profited by maintaining misconceptions about CYA. Even at this point the standards organizations are resisting the well established understanding of how CYA actually works.

 

[steveg_nh]

Sounds like government.