The quality of your water determines the amount of sets needed for optimal performance:

M-3 (3 sets) Regular Duty - homes up to 2,500 feet
M-4 (4 sets) Heavy Duty - homes up to 3,500 feet
M-5 (5 sets) Super Heavy Duty - homes up to 5,000 feet
Additional sets can be added if increased performance is deemed necessary.

To purchase, please visit The Energy SuperMarket