saw it was cloudy yesterday - couldn't see the deep end.

chlorine was nonexistent - busy at work past 4 days - forgot to test water - my mistake!

so i added several gallons of chlorine overnight, now water reading are: using taylor drop kit

TC 5.6
FC 4.6
TA 50
CA 210
pH 7.0 (been running it low for a few weeks to try to reduce the scale)

35000 gal, concrete in ground pool with DE filter.

Just curious on your thoughts why it was cloudy? algae/microorgs?