A little searching on the availability of algae in lakes and
streams or water going through the turbines of hydroelectric
power plants gives values of 50 mg/liter (10 cubic meters/pound)
for the Colorado River and much more if there is an "algae bloom"
like the green one on Lake Mead (near Las Vegas, Nevada) a few years ago.
Gravity-powered filters (or centrifuges) for separation?
Fred
