This video is pretty interesting, but the reason I shared is at 18:10 where he shows how to make a useful homemade water filter system for about $75.
It's made with commercially available filters and food grade buckets and is good for 6,000 gallons of water.

He's a little goofy, but it seems like a good video. Skip to 18:10 if he is a little too silly



to save you time, so you have an idea what he makes....