do you need to turn off SWG when adding chemicals

[mphare]

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I run mine 6 hours a day...that's it. All you really need to do is to turn the water over in the pool twice daily and you're good to go. For instance if you have a 10,000g pool, and your pump can do around 28 gpm, then 6 hours is close enough. (10000/(28*60)=6)

OK, help me with your math..

It looks like 6 hours is enough to turn the pool over only once, not twice.

What am I missing?