Arrived on site to perform by annual system maintenance and cooling evaluation. Blew out water removal system with CO2. Chemically treated water removal system lines and heat transfer media coil pan with pan treatment spray. Replaced 20 x 20 filter provided by customer tested system in cooling and got an 18° temperature split. Got refrigerant pressures which were good for a cool morning wash down condenser with water informed customer heat transfer media coil was getting dirty. Recommended an HK clean in place. Present customer with options and she would like a print out of the options.