why do you want them to grow on the glass?
My algae spreads on rocks pretty good but not on glass which is what I want.
I don't want to see algae on glass.
But I just spotted a few on glass now......errrhhhhhh....don't like that.
I think I just want to let it happen naturally. Instead of using chemicals that could potentially cause something to go wrong. Thanks for you resposne though.
Have A Great Super Bowl Sunday.