Bay water quality/safety for swimming

I was swimming yesterday also - but in Playa Manzanillo. Same greenish water with poor visibility. Ron's right - it's probably algae and just the ocean adjusting to the change in temperature. I'm out snorkeling at least once a week - either there or at Las Gatas while my husband cleans the bottom of his panga. I wouldn't swim at play principal, but after waiting a day or two after rains, I'd swim anywhere else in the bay.