Which Well Water Filter Do You Actually Need?
Number copied. Text it from your phone: 443-277-2204.
The filter you need depends on what is in your water, and most wells need one or two systems, not the whole lineup. Of 344 well tests my customers have sent in, more than half showed one of the four big problems or none of them, and only 4 showed all four: low pH, hard water, iron or manganese, and bacteria. So start with a lab test, then match each problem it finds to the one system that fixes it.
A caller in New Hampshire read me his lab report in September: "Calculated hardness, 42 PPM or 2.5 per gallon." I told him, "You're fine. You don't need a softener. As long as it's below 7." His pH was 7.1, which I called perfect. His report did show bacteria, so the one thing he needed to order was a UV light.
Quick Answer
Test first, then buy only what the test calls for. Most wells need one or two systems.
- Test first. One $199 lab test checks pH, iron, manganese, hardness and bacteria from one sample. See what the test shows.
- Match each problem to one system. Sand: a sediment filter. Rust or black stains, or a rotten egg smell: an iron filter. Hard water: a water softener. Blue-green stains: an acid neutralizer. Bacteria: a UV light. See which system fixes which problem.
- Skip what your test does not show. More than half the wells my customers test need one system or none. See how many systems most wells need.
- Put them in order. Everything goes after the pressure tank. The sediment filter goes first and the UV light goes last. See the order.
What's in This Guide
Which system fixes which problem
Each problem below has its own system. You only buy the ones your water needs. Find the row that matches what you see or what your test says.
| What you notice | What the test shows | The system that fixes it | Price today |
|---|---|---|---|
| Sand or grit in the water, or dirt settled in the bottom of the toilet tank | You can see it yourself | A sediment filter (the 20 inch Big Blue) | $195 |
| Orange or rust stains, or black stains | Too much iron (over 0.3 ppm) or manganese (over 0.05 ppm) | An iron filter (the Fleck 2510 AiQ, 2.5 cubic foot) | $2,495 |
| Rotten egg smell from the hot and cold taps | Not on the lab test; your nose is the test | The same iron filter takes out the smell (up to 10 ppm) | $2,495 |
| White spots on glasses, scale on faucets, soap that barely foams | Hard water: 7 grains per gallon or more | A water softener. The 48,000 grain Fleck 5600SXT fits 1 to 4 people on water up to about 15 grains. | $1,995 |
| Blue-green stains in the sink or tub, or pinhole leaks in copper pipe | Acidic water: pH below 7.0 | An acid neutralizer (the Clack 2.5 cubic foot) | $1,495 ($1,695 if your pH is under 5.5) |
| Nothing you can see | Coliform or E. coli present | A UV light (the Viqua VH410) | $995 |
| Chlorine taste or smell (city water) | Chlorine from the city | A whole house carbon filter (the Clack 2.5 cubic foot) | $1,695 |
| Nothing you can see | Too much nitrate or arsenic (over the EPA limit) | A separate nitrate filter or arsenic filter | Nitrate filter $2,895 |
A few rows have a catch. A softener also takes out up to about 1 ppm of iron, so with hard water and a little iron, the softener may be all you need; above about 1 ppm, the iron filter goes in first. If your iron is over 0.5 ppm and your pH is low, the neutralizer has to be the backwashing kind ($2,195). For bacteria, retest if the first sample was rushed and shock the well; the UV light is the fix if it comes back. A rotten egg smell from the hot water only usually comes from the water heater's anode rod, not the well; my guide to the rotten egg smell in well water shows how to tell.
Sizing a softener? My softener size chart does it by people and grains, and how much a water softener costs has the full price picture. On city water the usual problem is chlorine, and my guide to well water vs city water covers what changes.
Text me your water test results
Send me the numbers and I'll tell you which of these you need, and what size.
8 AM to 5 PM Eastern, seven days a week. A real person, not a call center.How many systems most wells need
Most wells need one or two systems. Only 4 of 344 had all four problems. Those are the well tests my customers sent in through our lab kit. The count covers four problems, each with its own system: pH below 7.0, hardness of 7 grains or more, iron or manganese over the EPA line, and bacteria.
The most common single problem was hard water on its own. About 1 well in 6 showed none of the four, so that owner had nothing on this list to buy.
That is why I try to solve the immediate problem, as efficiently and effectively as possible and for the lowest amount of money possible. A pH of 5.5 is a common problem here in Maryland, and the answer is the 2.5 cubic foot non-backwashing neutralizer. It adds some hardness to the water, about 3 to 6 grains, so I may recommend a softener at the same time, but it is not absolutely necessary.
What buyers bought after their test
These are verified purchases, in the buyers' own words.
| Buyer | What they bought | What they wrote |
|---|---|---|
| Apr 2026 Verified buyer | An iron filter (1.5 cubic foot) | "This system saved me thousands over what other companies recommended." ... "I had rust and manganese and slightly acidic water." |
| Mar 2023 Verified buyer | An acid neutralizer and a sediment filter | "After having the water tested I found that it is acidic (pH 6) and showed some turbidity. After researching solutions I ordered a sediment filter and the Clack Neutralizer." |
| William H., Nov 2021 Verified buyer | An acid neutralizer (2.5 cubic foot) | "I noticed in the unfinished basement that the brass fittings on my Pex waterlines were all corroding. Had my water tested and it was acidic at 5.5." |
| James D., Jul 2020 Verified buyer | An acid neutralizer (2.5 cubic foot) | "It was exactly what we needed compared to all the others trying to sell us a backwashing system that we did not need nor the electronic Timer" |
| Westley W., Mar 2020 Verified buyer | An iron filter and a water softener | "Gave the values of water test, type and size of the well. Recommendation was accepted." |
What the well water test shows
One lab test checks pH, iron, manganese, hardness and bacteria. Sand and the rotten egg smell you find yourself. Our well water test kit is $199 and reports 53 contaminants and water-chemistry values, nitrate, arsenic and lead among them. Results usually take 2 to 4 weeks from the day you order.
What it does not show: hydrogen sulfide gas (the rotten egg smell), tannins, iron bacteria, radon or PFAS. For the smell, where you smell it tells you where it comes from.
If you have nothing yet, a home test kit from Lowe's or Home Depot checks the three that matter most, because "iron, pH, and hardness are the most important things," as I tell callers. A strip is a quick look, though, not a number to size a system on. A caller in July had strips reading around 30 ppm of iron, and his lab test said 53.6. The first thing I asked him was who tested the water and how they measured it. At that level you can't use a regular softener, and he needed two iron filters in a row.
On city water the questions change to hardness, chlorine and PFAS.
Watch every system in three minutes
In this video I walk the wall of the six main systems we sell for wells and answer two questions people ask me: does the order matter, and do I need every piece.
Two things have changed since I filmed it in April. The six systems on the wall now come to $8,870 to $9,070 at today's prices, depending on the softener size, not the $6,000 to $7,000 I said. And the order I give for a well with high iron is one case: when an acid neutralizer is in the mix, I set its place from your test.
The order the systems go in
Every system goes after the pressure tank. The sediment filter goes first and the UV light goes last. If your test calls for more than one, this is the line from the pressure tank to the house:
- Sediment filter.
- Iron filter.
- Water softener, after the iron filter and any neutralizer.
- Carbon filter, if you want one.
- UV light, last.
If your pH is low, an acid neutralizer goes in too, and I set its place from your test. My guide to the correct order for well water treatment explains why each one sits where it does.
Every tank ships empty, with the media in separate bags or boxes that go in at install, and drain tubing is not included. I recommend having a plumber do the install, and I'm a phone call away for your plumber; if you'd rather do it yourself, text me with any questions. A non-backwashing tank is just an inlet and an outlet. A backwashing tank or a softener also needs a drain line and an outlet for the valve. Several tanks in a row is the biggest job: a plumber takes 3 to 4 hours or more.
Frequently asked questions
What is the cheapest way to filter well water?
Buy only what your test calls for. If the only problem is sand, that is a $195 sediment filter. If it is only low pH, it is a $1,495 neutralizer. The $199 test keeps you from paying for a tank you do not need.
Do you need a filter if you have well water?
Not always. A well with good numbers needs nothing on this page. The New Hampshire caller's hardness and pH were fine, so the only thing he needed was the UV light his bacteria result called for. Test your well again every year: the EPA says to test a private well yearly for coliform bacteria, nitrates, dissolved solids and pH.
What is the best micron rating for a well water filter?
I recommend a 5 micron cartridge for a well's sediment filter. Put it in a 20 inch Big Blue housing so it does not cut down your water flow. VIQUA, the UV maker, calls for a 5 micron filter ahead of its UV lights. My micron rating guide covers the other sizes.
What's the best way to filter well water for drinking?
Treat the whole house for what your test shows first. Reverse osmosis under the kitchen sink is a separate step, just for drinking water. It takes out most dissolved metals and salts and part of the nitrate. It does not take out bacteria or the rotten egg gas. See what reverse osmosis removes.
How much does a whole house well water filter system typically cost?
Each of the six main systems costs $195 to $2,495 today. All six together come to $8,870 to $9,070, depending on the softener size. Most wells need one or two, so most homes pay for one or two of those. My guide to well water treatment system cost adds the plumber and the upkeep.
What is the best well water filter system for home use?
The best system is the one your test calls for. My pick for each test result, with today's price and the household each fits, is in my best-of guide.
Aidan Walsh
Co-owner & Residential Water Treatment Specialist, Mid Atlantic WaterAidan Walsh has spent 32 years in residential water treatment, the first stretch of it installing and servicing well systems before Mid Atlantic Water became an online supplier. Mid Atlantic Water is a family company; every recommendation on this site is based on what actually failed in the field and what fixed it. If you have a question this page did not answer, call 800-460-5810 or text him at 443-277-2204.
Aidan answers calls and texts 8 AM to 5 PM Eastern, every day.Number copied. Text it from your phone: 443-277-2204.