Choosing the right brackish water RO membrane
Brackish water sits between fresh and seawater on the salinity scale -- typically 1,000 to 10,000 ppm TDS, found in inland wells, some municipal supplies, and surface water sources. AMPAC brackish water RO membranes are engineered specifically for this TDS range, striking the balance between rejection performance and operating pressure that seawater-rated membranes do not need to solve.
Our brackish water RO membranes run at 150-400 psi and deliver 98-99.5% salt rejection at standard test conditions (2,000 ppm NaCl, 225 psi, 77 degrees F). That is a fraction of the 800-1,200 psi seawater desalination requires, which keeps pump sizing, energy cost, and system footprint down for facilities that do not need ocean-water capability.
Available element sizes
AMPAC stocks brackish water RO membranes in 2.5″ x 21″, 4″ x 40″, and 8″ x 40″ configurations to match standard pressure vessel diameters used across residential, commercial, and industrial RO systems. Element selection depends on your system's vessel diameter and required permeate flow rate -- our engineering team can confirm compatibility before you order.
Membrane life typically runs 2-5 years depending on feed water quality, fouling, and maintenance. Watch for rising product water TDS, declining flow, or rising differential pressure across the housing as signs it is time to replace.