Many thanks to everyone who weighed in on this thread from yesterday.
http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=105&topic_id=1577204 My sister is extremely grateful, and asked me to pass along the following notes and a new question:
"Wow. Lots of info. Thanks to everyone. I found a place . . . that sells that floc stuff, so I'll get some tomorrow. But really, there has been no rain or thunderstorm in YEARS - although it has been slightly overcast in the mornings for the past few days.
"I have a brush, 'cuz a few weeks ago, I got one and sent Tor to work on brushing off the patches. But at the time, the WATER was clear, just a few small patches of algae on the walls. Right now, I can't even SEE the walls, the water is too green! If you don't mind asking one more question...
is it safe to be in the water, to brush the walls, etc, when it's so green?"Thanks again.