Couple bags of shock bring it right back to life.
LOL...for that sized pool....more than just a couple of bags of shock.
I suppose the amount required for that mess would burn everyone’s eyes. Not good! Especially for the synchronized swimmers.
Barley straw works quite well.
How does it work?
“Barley straw does not kill existing algae, but it inhibits the new growth of algae. The exact mechanism is poorly understood, but it seems that barley straw, when exposed to sunlight and in the presence of oxygen, produces a chemical that inhibits algae growth.”
http://extension.psu.edu/natural-resources/water/ponds/barley-straw