cloudy days

duraleigh

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Apr 1, 2007
31,323
Sebring, Florida
#2
My guess, and it's a guess, is almost. Clouds do not block much UV rays which I believe are the primary reason for Cl loss. That said, they do block some so my assumption is you would use less but not much less...maybe 25%.

I usually don't respond with guessing but no one answered your post yet so this will bump it back up for someone who is more confidant with their reply.