PENTAIR 2550 GRO 2 sump Reverse Osmosis 3 piece Complete Filter Pack with Membrane
FITS PENTAIR GRO RO SYSTEMS
Set includes 1 x 5-micron carbon filter,1 x 5-micron sediment filter, 1 x Polishing inline filter and 1 GRO Pentair Encapsulated Membrane. Most Reverse Osmosis Drinking Water Systems require a new Membrane every 3-5 years and a set of filters every year.
The 2 bottom filters should be changed yearly.
How can you tell it's time to change the Membrane? Two signs that your membrane is failing are these: water production slows down to a trickle or the water has an "off" taste. Generally, under normal use, if your unit is installed on a SOFT water line (as it should be), your membrane will last 4-5 years. If it's hooked into a HARD water line, expect to replace your membrane every couple of years if not sooner.
Fits R/O units that look like this: