My report states “Flush diffusers to lower demand on compressor”. What does this mean?

This means that we flushed your diffusers to lower the PSI reading on your aerator.  The diffusers are located at the end of the aeration line in tank 2 (ATU).  The diffusers are small stones that create the air bubbles needed for bacteria growth.  When we flush the diffusers it relieves the pressure on the aerator, allows maximum air into ATU, and reduces the work load hopefully extending its life.