When Does an RO Membrane Actually Need Changing?
Not when the calendar says. A two-minute test tells you if your reverse osmosis membrane is still doing its job.
By Danny Lachhman · Owner, 360WATER Systems Inc. · Orangeville, Ontario
Reverse osmosis systems have two kinds of parts inside, and they age very differently. The prefilters — sediment and carbon — are on a schedule: roughly every 6 to 12 months. The membrane is not on a schedule. A membrane commonly lasts two to five years, and replacing it by the calendar is how money gets wasted.
The Test That Settles It
An RO membrane in good health rejects around 90% or more of the dissolved solids in your water. Test the tap water with a TDS meter, test the RO water, and compare. If your tap water reads 300 and the RO water reads 25, the membrane is doing its job. If the RO reading keeps creeping up toward the tap reading, the membrane is fading.
Signs people notice first: the taste slowly comes back, the storage tank takes longer and longer to fill, or the system seems to run and drain more than it used to.
What Actually Kills Membranes Early
Neglected prefilters. The carbon prefilter removes chlorine before it reaches the membrane — chlorine eats membrane material. Let the prefilters go two or three years and you’ll buy a membrane years ahead of time. The cheap parts protect the expensive part.
So the routine is simple: prefilters on schedule, membrane on evidence. If you want the numbers, bring a sample of your RO water and a sample of your tap water to the showroom — we’ll TDS-test both, free, and tell you honestly whether the membrane has life left in it.
← Back to the blog