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Water filtration installation in San Jose, whole-house and under-sink
A chemical taste at the tap, a fridge filter that clogs fast, or simply wanting cleaner drinking water. Filtration is a different job from softening, and the right system depends on what you want taken out.
Water filtration installation in San Jose is usually one of two systems: a whole-house catalytic carbon filter that reduces chloramine, taste and odor at every tap, or an under-sink reverse osmosis unit for drinking water. Standard carbon handles chlorine well but removes much less chloramine, so the media matters.
The job
Filtration or softening?
Filters and softeners solve different problems. A softener removes the hardness minerals that leave scale; it does not change taste or remove disinfectant. A filter changes taste and odor and reduces specific contaminants; it does not stop scale. Many San Jose homes end up with both, and the order at the main matters.
Scale and hardness are covered on our softener installation page. Whole-house filters get a bypass at the main just like a softener, so the house keeps water during service.
Cost factors
What changes the price of a filtration system
- System type Whole-house tanks cost more than under-sink units.
- Media Catalytic carbon costs more than standard carbon.
- Install point Garage mains are simpler than tight closets.
- Extras Fridge lines, prefilters and bypass valves.
- Upkeep Replacement filters and media over time.
Every job is priced after we see it; any published range is for planning only.
Your options
Whole-house carbon or under-sink RO?
One treats every tap; the other treats drinking water only, more thoroughly.
| Whole-house catalytic carbon | Under-sink reverse osmosis | |
|---|---|---|
| Where it works | Every tap and shower | One faucet at the kitchen sink |
| Main effect | Taste, odor and disinfectant reduction | Broad reduction of dissolved solids |
| Upkeep | Media replaced every few years | Filters yearly, membrane every few years |
| Water use | No wastewater | Some water goes to drain |
| Space | At the main, often in the garage | Under the kitchen sink |
Whole-house carbon filter
A whole-house filter sits at the main, after any softener and pressure regulator, so every fixture gets filtered water. Tank systems hold a bed of carbon media that lasts years between changes; cartridge housings cost less up front but need frequent swaps. We size the unit to your peak flow, so a shower and the washer running together do not drop pressure, and fit a bypass so the system can be serviced without cutting water to the house. A sediment prefilter protects the media where the supply carries grit.
Under-sink reverse osmosis
Reverse osmosis pushes water through a fine membrane, removing most dissolved solids along with many contaminants, and stores the result in a small tank for a dedicated faucet. It suits drinking and cooking water rather than the whole house. The install covers a cold supply tee, a drain connection with an air gap, the storage tank, and a faucet set in the sink or counter. We can also run a line to the refrigerator for filtered ice and water. Watts and other makers build systems we install.
Chloramine-rated catalytic carbon
Water systems that disinfect with chloramine, a compound of chlorine and ammonia, need catalytic carbon to reduce it effectively; ordinary activated carbon that works well on chlorine removes far less chloramine. So we specify catalytic carbon for whole-house systems here and size the tank for contact time, since chloramine needs longer exposure to the media than chlorine does. A filter sold as a generic chlorine filter may not do the job, which is why we check the media listing before installing.
Filter changes
A filter only works while its media and cartridges are within capacity. Sediment prefilters clog, carbon exhausts, and RO membranes foul faster when the water feeding them is hard. We set a change schedule for your system and water use, label the housings with the install date, and handle the changes if you would rather not. On existing systems installed by someone else, including Culligan units, we service the filters and check that the bypass and isolation valves still work.
What happens after you call
From water test to filtered tap
- 1
Water test
Hardness, and what you want removed.
- 2
Recommend
System, media and size.
- 3
Quote
Written, with upkeep costs.
- 4
Install
Bypass, housings and connections.
- 5
Flush and test
Media flushed, leaks checked.
- 6
Schedule
Change dates labeled on the unit.
Local context
Hardness and filter life in San Jose
San Jose Water counts water above 7 grains per gallon as hard, and that line matters when choosing filtration, because a filter does nothing for hardness. In homes above the threshold, scale fouls carbon media and RO membranes faster, so we test hardness before designing a filter system and put a softener ahead of it where the reading calls for one. The order at the main is softener first, then carbon, then any drinking-water unit at the sink.
Brands we service and install
FAQ
Water filtration questions
No. It removes hardness; a filter handles taste and contaminants.
Yes. RO is widely used for drinking and cooking water.
Not if it is sized for your peak flow.
It depends on the system; we label change dates at install.
Yes, from the RO unit or a dedicated filter line.
It reduces chloramine far better than standard carbon.
Yes, including filter and media changes.
Related work
Other Pipes, Water & Gas jobs we handle
Guide: Hard water in San Jose.
Plan a water filtration system in San Jose
Call any hour to book a water test and a recommendation.
Updated September 2026