By ion exchange. The tank holds 1.5 cubic feet of ResinTech SIR-100-HP, a nitrate-selective strong base anion resin in chloride form. As water flows through the bed, the resin swaps harmless chloride ions for nitrate ions and holds the nitrate on the bead. When the metered valve sees you've used enough gallons, it regenerates the bed with a sodium chloride brine (ordinary water softener salt), flushes the captured nitrate to the drain, and restores the resin to chloride form. It's the same mechanic as a water softener, with a resin engineered for nitrate instead of hardness.

Yes. Nitrite is also an anion and is captured by the same anion exchange process. The EPA limits are 10 ppm for nitrate (as N) and 1 ppm for nitrite, and a well with one frequently has some of the other, since nitrite is an intermediate step in the same contamination chain (fertilizer, septic, animal waste). We recommend testing for both before and after install so you can see the numbers come down on a certified lab report.

The 6 GPM unit (1.5 cu ft, 10x54 tank) fits homes with 1-2 bathrooms or 1-3 people. The 10 GPM unit (2.5 cu ft, 13x54 tank) fits homes with 3+ bathrooms or 4+ people. This 6 GPM unit is the right size for the typical 1-2 bath well home and is our most popular configuration. If your home has unusually high flow demands, two units can be plumbed in parallel. When in doubt, call or text us with your bathroom count and water test and we'll size it in two minutes.

Roughly what a water softener uses: most families spend $100-200 per year on water softener salt. Because the valve is metered demand (it counts actual gallons instead of regenerating on a timer), it only uses salt when the resin genuinely needs regeneration. Higher nitrate levels and higher water use mean more frequent regenerations. One tip on hard water: use softened or low-hardness water for brine makeup, or calcium carbonate scale will build up in the brine system over time.

Sulfate competes with nitrate for capacity on any anion resin. SIR-100-HP is specifically engineered to prefer nitrate, so unlike generic type 1 or type 2 anion resin it will not dump captured nitrate back into your water even after the sulfate break. But high sulfate still reduces working capacity, which changes how the system should be sized and how often it regenerates. If your lab report shows elevated sulfate, call us with the numbers before ordering and we'll confirm the right configuration.

Maybe, and we'll give you the honest version. This system removes nitrate at every tap in the house: cooking, bathing, ice maker, all of it. An under-sink RO treats one faucet. For most families over the 10 ppm limit, the whole-house system alone does the job. For households with an infant under 6 months or a pregnancy, the gold standard is both: whole-house ion exchange plus an RO polishing the kitchen tap where formula and drinking water come from. If your levels are moderate and budget is tight, an RO alone may honestly be the better first buy - send us your test and we'll tell you.

Years. Unlike single-use media, SIR-100-HP regenerates with sodium chloride brine every cycle, so the bed restores itself instead of wearing out with each gallon. Eventually, after years of service, resin beads physically degrade and capacity declines; at that point you rebed the tank with replacement SIR-100-HP resin (we sell it by the cubic foot) rather than replacing the system. An annual nitrate test on the treated water is the reliable way to confirm the bed is still performing.

Because softener resin is a cation resin: it removes calcium and magnesium (hardness), which are positively charged. Nitrate is an anion, negatively charged, and passes straight through softener resin. The reverse is also true, which is why the treatment order matters: the softener goes upstream to remove hardness, and the nitrate system goes after it. Removing hardness first protects the nitrate resin and keeps the brine makeup water soft.

Yes, always. Nitrate is colorless, odorless, and tasteless, so a certified lab test is the only way to know your level, and we need nitrate, nitrite, sulfate, and hardness to size the system correctly. The EPA recommends well owners test every 1-3 years, and more often if you live near farmland, since nitrate spikes in spring and summer when fertilizer and manure spreading pick up. Order our well water test kit (53 contaminants, certified lab) or send us the report you already have, and we'll personally confirm the right system before you spend anything.