You must have missed this paragraph:Is it right that I didn't read about any skimming in the article?
Filtration:
A 30 gallon sump sits below the tank in my "fish" closet. One GenX Mak4 external pump (1,200 gallons per hour) draws water from the sump, passes the water through a Ã"šÃ‚¼ HP Universal Marine in-line chiller before ultimately returning it to the tank. An identical Mak4 pump drives water from the sump to an in sump ETS 750 Reef-Devil Gemini protein skimmer.