Our 9-Stage Process
Every stage, published — because “purified” on its own means nothing.
How Clairemont Water Store purifies its water
Clairemont Water Store purifies San Diego municipal water through nine stages: three graded sediment filters at 25, 5 and 5 microns, an activated charcoal bed that strips chlorine before it can reach the membranes, reverse osmosis through sub-1-micron membranes, continuously ozonated sealed storage, USA-sourced palm-husk activated charcoal, a final 1-micron filter, and a wide-spectrum UV-C sterilisation chamber sited immediately before the faucets. City water arrives at 600–1500 ppm total dissolved solids and is dispensed at 3–5 ppm, never above 10 ppm — more than 99.1% removed. RO membranes are replaced when the reading hits 7 ppm or at 250,000 gallons, whichever comes first, and the tanks are flushed and sanitised 2 times a year on top of being continuously ozonated.
600–1500ppm
City water, as it reaches us
3–5ppm
At our water bar faucet
9.5pH
Alkaline line, approximately
Almost every water store in San Diego will tell you its water is purified. Very few will tell you what that means at their shop. These are our nine stages, in the order the water passes through them, with the specification of each — so you can compare us against anyone.
Stage 1: Sediment pre-filter
25 micron
Catches the coarse material — grit, rust, scale and pipe debris picked up between the treatment plant and our door. It exists to protect everything downstream from being blinded by particles a finer filter would choke on.
Stage 2: Second sediment filter
5 micron
A five-fold step down, taking out the fine particulate the 25-micron stage passes. Staging the filtration this way means each cartridge does the job it is suited to and lasts as long as it should.
Stage 3: Activated charcoal
chlorine, metals and chemical reduction
Adsorbs chlorine and chloramine, dissolved organics, and the taste and odour compounds that come with municipal treatment. This stage is also what protects the RO membrane — chlorine degrades membrane material, so it has to be removed before the water ever reaches it.
Stage 4: Third sediment filter
5 micron
A polishing pass after the carbon bed, catching any fines that carry over from the charcoal so the membrane sees the cleanest possible feed water.
Stage 5: Reverse osmosis
pumped through sub-1-micron membranes
The stage that does the heavy lifting. Water is pushed under pressure against a semipermeable membrane whose pores are finer than a micron; water molecules pass, and dissolved solids, salts, metals and the great majority of contaminants are rejected and flushed to drain. This is where 600–1500 ppm becomes single digits.
Stage 6: Ozone saturation in sealed storage
continuous, in sealed tanks
Purified water is stored under continuous ozone saturation. Ozone is a powerful oxidiser that inactivates microorganisms on contact and then reverts to ordinary oxygen, leaving no chemical residue and no taste behind — which is why it suits stored drinking water where a chlorine residual would not. Storage is where untreated water would be vulnerable, so it is treated continuously rather than periodically.
Stage 7: Palm-husk activated charcoal
5 micron, USA-sourced
A second carbon stage after storage, using palm-husk carbon for its high microporosity. It polishes taste and removes any residual organics, so what reaches the faucet tastes of nothing at all.
Stage 8: Final sediment filter
1 micron
The last mechanical barrier before dispensing — one micron, an order of magnitude finer than where the train started.
Stage 9: Wide-spectrum UV-C sterilisation
immediately before the faucets
A germicidal ultraviolet chamber sited at the very end of the line, immediately before the indoor water bar faucets and the outdoor vending machine. UV-C light disrupts the genetic material of any organism passing through it so it cannot reproduce. It adds nothing to the water and changes neither taste nor chemistry. Placing it last means the water is sterilised after every pipe it will ever touch.
When we change the membranes
An RO membrane does not fail on a schedule, it degrades with use — so we replace ours on a reading, not on a calendar. When the water bar measures 7 ppm, the membranes come out. There is a second trigger at 250,000 gallons of throughput as a backstop, but in practice the ppm reading always gets there first.
Storage is the other place water quality is quietly won or lost. Our tanks are sealed and held under continuous ozone saturation rather than being treated periodically — and we still flush and sanitise them 2 times a year.
What we make — and what we don't
We make exactly two kinds of water, both from the process above: ultra-purified reverse osmosis water and alkaline water at around pH 9.5. That is the whole menu.
We do not carry distilled water, deionized (DI) water, spring water, or cases of bottled water. Those are different products made by different processes, and we would rather say so here than have you find out in the parking lot.
If you came looking for distilled or DI specifically — for a CPAP machine, a car battery, a humidifier, an iron, an aquarium or lab work — that is a real requirement and we are not going to talk you out of it. Our purified water measures 3–5 ppm, which is a fact you are welcome to weigh; whether it suits your equipment is your call to make, not ours to promise.
Common questions
What is the TDS of your water?
3–5 ppm at the water bar, and never above 10 ppm. San Diego city water reaches us at 600–1500 ppm, so that is more than 99.1% of dissolved solids removed.
How often do you change the RO membranes?
When the water bar reads 7 ppm, or at 250,000 gallons of throughput — whichever comes first. In practice the ppm trigger always comes first, which is the point of having both: the gallon count is a backstop, the reading is the real rule.
Do you use reverse osmosis?
Yes — stage five. Water is pumped under pressure through sub-1-micron membranes, which is where the great majority of dissolved solids are removed. It is one stage of nine, not the whole process.
How do you keep stored water clean?
Storage tanks are sealed and continuously saturated with ozone, which inactivates microorganisms and then reverts to ordinary oxygen leaving no residue or taste. On top of that the tanks are flushed and sanitised 2 times a year.
Is the water sterilised before it comes out of the faucet?
Yes. A wide-spectrum UV-C chamber is the ninth and final stage, sited immediately before both the indoor water bar faucets and the outdoor vending machine — so the water is sterilised after the last pipe it will ever touch, not before.
Do you sell distilled water?
No. We make purified reverse osmosis water and alkaline water. Distillation is a different process — water boiled to steam and condensed back — and we do not offer it. Worth knowing before you drive over.
Do you sell deionized (DI) water?
No. Deionization strips ions using exchange resins and is a different process from ours. We do not carry it.
Do you sell spring water or bottled water by the case?
No. We are a refill station — you bring a container and we fill it with purified or alkaline water by the gallon. We are not a spring water source and we do not sell cases of bottled water.
This water is dispensed at our indoor water bar and at the 24-hour outdoor water vending machine. The indoor bar also serves alkaline water at around pH 9.5.