Whole House Water Filters for Well Water

Start with a water test

EPA says to test a private well every year for total coliform bacteria, nitrates, total dissolved solids and pH. CDC adds that you can ask your health department about other tests, such as arsenic, lead, radium and volatile organic compounds. Use a state-certified lab; CDC says your health department or county can give you a list.

For filter shopping, ask for iron, manganese, hardness, hydrogen sulfide and turbidity too. Our well water testing guide covers sampling and what each result means.

Private wells aren't covered by federal drinking water rules, which Penn State Extension points out, so EPA's limits are the yardstick you use yourself. The health limits you'll see most often:

If a health contaminant is over the limit, EPA says to contact your public health department for the steps to take and to retest to confirm it. Don't buy equipment off a single result.

Match the filter to the problem

Sediment

Almost every well benefits from a sediment filter right after the pressure tank. It protects everything downstream, from the softener injector to the UV sleeve. Cloudy or gritty water has its own page: sediment and cloudy water.

Iron and manganese

Penn State Extension matches the treatment to the level:

• Under 2 mg/L of dissolved iron: polyphosphate can sequester it, but it doesn't remove it.
• Under 5 mg/L of dissolved iron, with pH above 6.7 and hardness of 3 to 20 grains per gallon: a water softener is recommended.
• 3 to 10 mg/L of combined iron and manganese: an oxidizing filter such as manganese greensand.
• Above 10 mg/L combined: oxidation, such as chlorination, followed by filtration.

Birm filters need a pH of at least 6.8 for iron and 7.5 for manganese. More detail on iron in well water and manganese.

Hydrogen sulfide (rotten egg smell)

Penn State's numbers: activated carbon works below about 1.0 mg/L, oxidizing filters handle up to 2 to 3 mg/L, aeration usually isn't used above about 2 mg/L, and chlorination is most often used above 6.0 mg/L. If the smell is only in the hot water, the cause is often the water heater's magnesium anode rod, and Penn State says replacing it with an aluminum rod should eliminate the odor. See sulfur smell in well water.

Low pH

Acidic water eats copper pipes and leaves blue-green stains. Penn State says neutralizing filters raise pH by adding calcium, which also makes the water harder. Chemical feed systems that inject an alkaline solution ahead of the pressure tank reduce corrosivity without adding hardness. If you go the neutralizer route, put it before the softener.

Bacteria

Coliform bacteria in a well is first a well problem. EPA says bacteria can sometimes be dealt with by disinfecting the well with chlorine, ozone or UV light. Shock-chlorinate, retest, and look for how the bacteria got in, such as a bad well cap. If it keeps coming back, a UV system is the usual answer. See bacteria in well water and shock chlorination.

Health contaminants

Arsenic, nitrate and uranium aren't things a sediment or carbon filter takes care of. Treatment is specific to the contaminant and often done at the kitchen tap rather than for the whole house. Get advice from your health department first, then pick a system certified for that contaminant. Our nitrates page covers that one in detail.

Put them in the right order

Water should pass through the equipment in this order, starting at the pressure tank:

1. Sediment filter
2. Acid neutralizer, if needed
3. Iron, manganese or sulfur filter
4. Water softener
5. Carbon filter, if used
6. UV last, so the water it treats is as clear as possible

The order matters because each step protects the next. Iron fouls softener resin, sediment scratches valve seals, and cloudy water shields bacteria from UV light. If you're adding a softener, our water softeners for well water page covers the iron limits.

What to skip

Skip the "one tank does everything" well system bought without a test. You'll pay for media you don't need and still miss the thing you do. Skip treatment for a problem you don't have, too. Hard water that doesn't bother you, at levels under 7 grains per gallon, generally doesn't need treatment, according to Virginia Cooperative Extension. And don't count on a pitcher or fridge filter to handle bacteria.

Install notes

• Leave room and add a bypass. Every system needs service, and a bypass lets you keep water on while you work.
• Backwashing filters (iron, sulfur, neutralizer, softener) need a drain and enough flow from the well pump to backwash. Check the filter's backwash rate against your pump before you buy.
• Every filter costs you some pressure. A stack of cartridge housings on a marginal well system will be noticeable at the shower.
• HomeGuide puts simple filter installation at $150 to $300 and multi-stage installation at $500 to $2,000.

What it costs to run

HomeGuide's 2026 figures put a well water filtration system at $1,500 to $5,000 installed on average. Upkeep is real money: sediment cartridges at $5 to $30 every 1 to 3 months, carbon cartridges at $20 to $80 every 6 to 12 months, and a UV lamp at $50 to $150 a year. HomeGuide puts total annual maintenance at $100 to $500.