PENTAIR GRO-75 Reverse Osmosis Complete Filter Pack with 75 Membrane
FITS PENTAIR GRO RO SYSTEMS
Set includes 2 x 5-micron carbon filters, 1 x 5-micron sediment filter and 1 TFC (thin film composite) 75 gallon per day 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 3 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 the full 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: