Does Reverse Osmosis Remove Minerals From Water?
22 September 2026 · Waimin
Yes. Reverse osmosis is designed to strip almost everything out of water, and it does not distinguish between what you want gone and what you might want to keep. Contaminants go, and the naturally occurring minerals go with them.
That is not a fault in the technology. It is the technology working exactly as intended. It does leave a question most filter manufacturers skip over: what happens to water once everything has been taken out of it?
How reverse osmosis works
A reverse osmosis system pushes water through a semi permeable membrane under pressure. The openings in that membrane are extraordinarily small, small enough that water molecules pass through and most dissolved solids do not.
The membrane has no way to sort the dissolved solids it blocks. It cannot tell a contaminant from a mineral, because at that scale the difference between them is chemical rather than physical. Anything that does not fit is rejected, whatever it happens to be.
That is precisely why reverse osmosis is so effective, and also why remineralization keeps coming up in the same conversation.
Which minerals are affected
The minerals most commonly reduced by reverse osmosis are:
- Calcium, one of the most abundant minerals in most natural water sources
- Magnesium, which contributes noticeably to how water tastes
- Potassium, usually present in smaller quantities
- Sodium, which in trace amounts affects mouthfeel rather than saltiness
Distillation and deep purification reduce these in much the same way. If your water has been through any of those processes, the mineral question applies to you as well.
Why people notice the difference
The most common observation is about taste. Water with no dissolved minerals is often described as flat, thin, or empty. Minerals are a large part of what gives water character, which is why bottled mineral waters are sold on their mineral profile rather than on purity alone.
If you have health questions about mineral intake, those are worth putting to a qualified healthcare professional rather than to a water company. What we can speak to is taste, character, and what filtration changes about the water itself.
How to put minerals back
Remineralization means adding selected minerals back into water after it has been filtered. The order matters more than people expect.
A remineralizer has to sit after your filter. Installed the other way around, the filter would strip the minerals straight back out. That is the single most common mistake when people attempt this themselves.
What to look for
- It fits after your existing filtration rather than replacing it
- It works automatically, with nothing to dose or remember day to day
- The cartridge has a stated service life, so you know when to replace it
- It connects to tubing you already have rather than requiring new plumbing
Where Waimin fits
Waimin is an inline remineralizer that installs after your existing filter. Water flows through the unit on its way to your tap, and the cartridge adds calcium, magnesium, sodium and potassium back in, along with trace elements from Himalayan salt.
It connects by push fit to the quarter inch or three eighths inch tubing most systems already use, and installation takes under an hour. Once it is in there is nothing to operate. Replace the cartridge at 1,000 litres or 12 months, whichever comes first.
To work out what that means for your household specifically, the cartridge life calculator estimates it from how many people you are and how much you drink.
Common questions
Does remineralizing undo the filtration?
No. The filter removes what you do not want, then the remineralizer adds back a selected set of minerals. The contaminants your filter removed do not come back with them.
Does it work with distilled or purified water?
Yes. Waimin is designed for reverse osmosis, distilled, purified and filtered water systems. The common factor is that all of them reduce minerals along the way.
Do I need to replace my existing filter?
No. A remineralizer is an addition to the system you already have, not a replacement for it. Your filter carries on doing its job.
How often does the cartridge need replacing?
At 1,000 litres or 12 months, whichever comes first. There is more on servicing, compatibility and warranty on the frequently asked questions page.