# Acid Neutralisers for Corrosive Water: What They Cost > How acid neutralisers treat corrosive well water, plus installed cost, media life, and sizing math. Canonical: https://watertreatmentpro.com/water-neutralizer/ Last updated: 2026-11-09 Acid neutralisers treat corrosive water by raising its pH before it enters your plumbing. They are typically installed as whole-house systems after a lab water test confirms low pH and identifies the right media. Choosing the wrong media or skipping the test can leave pipes unprotected or waste money on unnecessary equipment. Corrosive water usually has a pH below 7.0 and low alkalinity. It can leach copper from pipes and leave blue-green stains on fixtures. A neutraliser does not remove hardness or iron; it adjusts pH only. If your water also tests hard, you may need a water softener in addition to a neutraliser, which changes the installed cost math. ## How Acid Neutralisers Work There are two common whole-house approaches. A backwashing filter tank filled with calcite or magnesium oxide lets water flow through a bed of sacrificial media. As corrosive water contacts the media, it dissolves a small amount of calcium or magnesium, raising pH. The tank backwashes periodically to reclassify the bed and prevent channeling. A soda ash system uses a small pump to inject a sodium carbonate solution into the water line, usually upstream of a pressure tank or contact tank. This works well for very low pH where a calcite bed might dissolve too quickly or require too much maintenance. Soda ash adds sodium to the water, so households monitoring sodium intake should note the change. Both systems are point-of-entry, meaning they treat all water entering the home. They are not under-sink drinking water filters and do not replace reverse osmosis for dissolved solids reduction. ## Sizing and Load Math Sizing starts with the water test. You need pH, alkalinity, hardness, iron, and manganese. Flow rate matters too. Most whole-house neutralisers are sized for 8 to 15 gallons per minute, matching typical household peak demand. For a backwashing calcite system, media consumption depends on how far the pH must rise. If your water enters at pH 6.0 and you target pH 7.0, the media dissolves faster than if you start at pH 6.5. A typical residential tank might hold 1 to 3 cubic feet of media. At average use, expect to add media every 1 to 3 years. This is an estimate; actual life varies with water chemistry and daily volume. Soda ash systems are sized by injection rate. A pump might dose 50 to 100 parts per million of soda ash solution. If your household uses 300 gallons per day at 100 ppm, that is roughly 0.25 pounds of soda ash daily, or about 90 pounds per year. Solution tanks must be refilled on a schedule based on actual usage. ## Installed Cost and Media Expense A whole-house acid neutraliser typically costs $800 to $2,500 installed, including the tank, media, control valve, and basic plumbing connections. This is an estimate. A soda ash system with a chemical feed pump and solution tank can fall in a similar range but adds ongoing liquid media costs. By comparison, a water softener runs $1,200 to $4,500 installed, with salt at $120 to $400 per year. If your water test shows both low pH and hardness above 7 grains per gallon, you may need both systems. See /how-much-does-a-water-softener-cost/ for softener pricing detail and /water-softener-installation-cost/ for installation variables. Media replacement is the main recurring cost. Bulk calcite might cost $100 to $300 per refill depending on tank size and local pricing. Soda ash is sold by the pound or in solution tanks, with annual cost scaling with water use and starting pH. These are estimates; get a quote after your water test. ## Maintenance Requirements Backwashing neutralisers need a drain connection and electricity for the control valve. The backwash cycle uses water and salt is not involved. You should check the media level annually and top off the tank before the bed runs low. If the media exhausts completely, pH drops and corrosion returns. Soda ash systems require refilling the solution tank and checking the pump for wear. Injection lines can clog, and the pump tubing may need replacement every few years. Because soda ash adds sodium, some homeowners install a reverse osmosis drinking water system at the kitchen sink. Under-sink RO costs $300 to $900 installed, with running costs of $60 to $150 per year. See /reverse-osmosis-system-cost/ for detail. Neither neutraliser type removes bacteria. If your well test shows coliform or other microbes, a UV system is a separate consideration. See /uv-water-purifier-cost/ for pricing. ## When to Combine With Other Equipment Water treatment is sequential. Test first, then select equipment in this order: sediment filtration if needed, pH adjustment, then hardness or contaminant reduction. A whole-house filter costs $500 to $1,800 installed and may be warranted if your water also carries sand or silt. See /whole-house-water-filter-cost/ for comparison. If your water test shows iron above 2 to 3 parts per million, a softener alone may not handle it, and an iron filter at $800 to $2,500 installed may be necessary. See /iron-filter-cost/. If hardness is the primary issue and pH is acceptable, a softener may be the only equipment needed. For well owners, a full lab test costs $40 to $150. That is the first step before buying any neutraliser. See /well-water-treatment-cost/ for broader well equipment context. ## What to Expect After Installation After installation, retap water after 48 to 72 hours to confirm pH has moved into the target range. If pH remains low, the media may be undersized or the injection rate too low. If pH climbs too high, the system may be overcorrecting, which can cause scaling in some plumbing. Label all costs as estimates until a local installer quotes your specific plumbing layout and water chemistry. Equipment second, water test first. ## Bottom Line Acid neutralisers are a targeted tool for corrosive, low-pH water. They protect plumbing and reduce staining, but they do not soften water or remove contaminants. Start with a lab test, size for your flow rate, and budget for media replacement every few years. If your water has multiple issues, combine equipment in the right order rather than buying a single product that claims to do everything. Next, compare [how much does a water softener cost](https://watertreatmentpro.com/how-much-does-a-water-softener-cost/), [water softener installation cost](https://watertreatmentpro.com/water-softener-installation-cost/), [whole house water filter cost](https://watertreatmentpro.com/whole-house-water-filter-cost/) before you commit.