Upon my arrival I performed a 6 month checkup on 1 heat pump system. Flushed and treated the water removal system, replaced the air filter, washed condenser coil using water, cleaned and treated the electrical cabinet then verified system safety and performance. I found everything performing to manufacture specifications at this time. Did speak with the customer about the bacterial growth present inside the air handler. They will let us know if and when they want to move forward with treatment.