Commercial Reverse Osmosis Installation in Phoenix

A commercial under-sink RO install is the same hardware as a home unit, in a different setting: a 5-stage filter set, a storage tank, a dedicated faucet and a reject line to the drain. We install 5-stage systems with an optional UV stage, and we put the filters and tank where a staff member can reach them without emptying a cabinet. The tank and filters sit under the sink, and the RO faucet sits on the counter or the sink deck.

It suits a break room, a cafe's drinking-water tap, a dental or medical front office, a salon or a small kitchen that wants drinking water without hauling bottles. It does not feed a dish machine, an ice machine or a coffee brewer unless the manufacturer says so. For ice machines, see restaurant ice machine water filtration.

An RO system needs its own faucet. If your sink has a spare hole for a soap dispenser or sprayer, the faucet can use it. If not, a hole has to be drilled. Granite, quartz and other stone counters are a special case. We bring in a stone fabricator to drill the hole, because a cracked slab costs far more than the system. Tell us the counter material when you call, so we can plan the visit.

If you serve food or drink, Maricopa County's plan review guide has two RO rules. First, an approved, testable, high-hazard continuous pressure backflow preventer, such as an RPZ, goes immediately upstream from any RO system. Second, copper and brass cannot touch water from an RO system, so nothing downstream of the RPZ or the RO unit can be copper or brass.

That second rule catches DIY installs. Brass faucets, brass fittings and copper stubs are everywhere in a commercial sink, and none of them can sit on the RO side. We plumb the RO line with approved materials and a faucet that fits the rule. If the system re-mineralizes the water, the county requires water sampling. See soda and ice machine backflow for the other devices the county asks for, and plan review requirements.

Phoenix's 2025 report lists total hardness of 10 to 17.6 grains per gallon, and pH as high as 8.8. That matters because manufacturers set limits. One manufacturer's installation manual lists a maximum hardness of 10 grains per gallon at 6.9 pH, and says membrane life depends mostly on the pH and hardness of the supply. If supply pH is 6.8 to 7.7, the membrane may last well over a year, but it may last as little as 6 months when pH is 8.5 to 10, because a higher pH weakens it.

So the honest sizing question for a Phoenix business is whether the incoming water is inside the unit's limits. If hardness is above the spec sheet, a softener or a different pretreatment ahead of the RO is worth considering. See reverse osmosis versus a water softener and our water softening page. Another thing to check on the label is the maximum chlorine, and the pre-filters do that job.

Follow the manual for your model, and write the install date on the housings. The same manufacturer's manual says to replace the pre-filter and post-filter cartridges at least every 6 months of use, sooner if they clog, and to replace the membrane when output or taste changes. Other makers publish different numbers, and this is why we leave the manual with you. Our guide on RO filter replacement explains the signs.

One warning from a filter maker's sanitizing bulletin: never run a chlorine-based sanitizing cartridge through a system with the RO membrane still installed. The membrane is chlorine-sensitive. Remove it first, sanitize, then flush at least five gallons before putting it back.

We check the supply pressure and the sink first, set the faucet, connect the supply with a proper fitting, run the reject line to the drain with an air gap where the unit calls for it, then flush and test. The manufacturer's manual notes it can take 1 to 4 hours before the maximum flow is available at the faucet. Learn more in what to expect from an RO install.

EPA says RO wastes water and that filtration may be enough in some cases. If your complaint is chlorine taste or sediment, a carbon filter may do it for far less water. If the problem is scale on equipment, RO at one tap does nothing for the dish machine. And if the water is for coffee or ice, follow the equipment maker, since some say to avoid softened or demineralized water. Ask us before you buy; we will tell you if a simpler filter does the job. See whether RO is worth it.

Tell us the sink, the counter material and what the water is for. We offer free estimates and upfront pricing before work starts, and we are licensed and insured.