PENTAIR 2550 GRO 50 Reverse Osmosis Replacement Filter Set Yearly
Reverse Osmosis Filter Set contains 1x 5-micron carbon block filter and 1x 5-micron sediment filter.
Filters should be changed yearly on city-treated water under normal use and when connected to a SOFT water supply.
Filters should be changed every 6 months on private wells or when reverse osmosis is connected to a HARD water supply.
The sediment filter is the first one on the line and the carbon filter should be installed in the second housing.
If your RO has 2 filters on the bottom and a membrane (any type) across the top.