HydroLogic Stealth RO Membrane for RO150 and RO300, 150 GPD (HL 22121)

Stealth RO Membrane: The 150 GPD Element Behind the Stealth-RO

This is the reverse osmosis element that does the purifying in a HydroLogic Stealth-RO system. HydroLogic lists it as part HL 22121, a 150 GPD thin-film composite membrane. The Stealth-RO150 uses one element, and the Stealth-RO300 uses two. It is the third stage in the system, after the sediment filter and the carbon block. When new, it should remove about 98% of the dissolved solids in the incoming water. HydroLogic gives the membrane a useful life of six months to two years. Where it lands in that range depends on source water PPM, how much water you make and how well the pre-filters are kept up. High iron or silica in the feed water shortens the life. Clean water and regular carbon changes can stretch it past two years. Chlorine is hard on thin-film membranes, so the carbon stage ahead of it matters. A weekly power flush of about five minutes helps clear scale from the membrane surface. Using non-original membranes voids the Stealth-RO warranty.

Knowing When to Fit a Replacement RO Membrane

HydroLogic gives two signs that the membrane is due. The first is rejection: test the source water and the purified water, then compare the readings. If the element now removes less than about 90% of the source PPM, it is time to change. The second sign is a big drop in purified water flow. Change the pre-filters first, since clogged cartridges also slow the flow. If flow stays slow with fresh pre-filters, the membrane is worn. To swap it, pull the white 1/4 in tubing and lift that end of the housing from its clip. Twist off the membrane cap with the filter wrench and draw the old element out with pliers. Push the new one in with the two black O-rings leading, until it bottoms out. Thread the cap back on, check its O-ring and reconnect the tubing. Run the system for 30 to 45 minutes and discard all of that water to flush out the preservative. PPM readings can take up to a day to settle at their lowest point.

Key Features

• 150 GPD thin-film element: The RO stage of the Stealth-RO system.
• Fits RO150 and RO300: One element in the RO150, two in the RO300.
• About 98% TDS removal: Expected rejection from a new membrane.
• 6 months to 2 years of life: Depends on source PPM, use and pre-filter care.
• Clear change signals: Rejection under 90% or a lasting drop in flow.
• OEM part HL 22121: Keeps the Stealth-RO warranty intact.

Technical Specifications