I have seen a few of these builds before. This one makes me a little nervous as its using soda bottles for the tanks. It seems expensive to build too for a “cheap” build since the author is using alot of higher end parts with a free compressor from a frig. I would think they would have cheaped it out a bit more. Or…just buy a cheap compressor at Harbor Freight.
https://www.instructables.com/id/Makett-Airbrush-Compressor/