2 system ac pm check complete. Changed filters. Added chlorine tablets to condensate pump. Checked mechanical and electrical components, all in good shape. Chemically washed condenser coils and applied rust proof waxing. Recommend surge protection to protect units from lightning strikes and power surges. Recommend apco air purifiers to keep evap coils clean, prevent mold, and kill germs and viruses, essentially for better air quality. Systems operating normal at this time.