I have personally spoken to several HVAC technicians about sulfur gasses out of a well entering your home and in the A/C and cause formicary corrosion to the evaporator coil. Are the sulfur gasses the only harm to your coil?

1.The retired tech, my neighbour that installed my new 13 SEER Rheem Package unit(old one was only 7 years old!) advised me to install an Outdoor Aerator System to remove sulfurgasses from my well water.

2.Another Tech advised me to spray the coil with ArmorCoil(www.armorcoil.com) to protect the coil.

Any advice from anybody? Obvious the ArmorCoil will be the most economical way, or are there any other suggestions?
My new unit was installed 4 days ago and I would like it to last longer than 7 years.

Ron