Upon my arrival I performed a 6 month checkup on 1 heat pump system. Flushed and treated the water removal system, washed the condenser coil using water, cleaned and treated the electrical cabinet with electrical insecticide then verified system safety and performance. I found the system to be operating to manufacture specifications at this time. I spoke with the customers about the bacterial growth that is still within the system but no further action is going to be taken at this time.