Diagnose my water
On a well or city water, start with what you notice at the tap and we'll point you to the likely cause and the test that confirms it. Just want better drinking water? We'll match you to the right filter instead — before you spend a cent on treatment.
Well water
Answer a few questions about what you see, smell, and taste, and we'll point you to what's likely in your water and the test that confirms it. Use it to decide what to test for before you send off a sample.
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Match what you're seeing, smelling, or tasting
Iron a metallic smell · orange / red-brown stains · black or dark-brown stains · a metallic taste · a colored tint in the glass · falling water pressure · rusty slime in the tank
The metal behind orange rust stains and a metallic taste. Dissolved 'clear-water' iron is invisible until it hits air; it's removed by oxidation and a backwashing iron filter.
Manganese black or dark-brown stains
Leaves black or dark-brown stains and specks on fixtures and laundry. Often handled by the same oxidizing filters as iron, but a test confirms the level.
Confirm with a test → We don't have a dedicated fix guide for this yet — start by confirming it with a test.
Hydrogen sulfide (sulfur) a rotten-egg smell
The gas behind well water's rotten-egg smell. It's removed by oxidation — adding air or another oxidizer so the sulfur turns solid and filters out.
Hardness white, chalky scale · a bitter or soapy taste · scale buildup and spotting
Dissolved calcium and magnesium that leaves chalky scale, spots on glasses, and poor lather. Treated with a softener or a salt-free conditioner.
Confirm with a test → We don't have a dedicated fix guide for this yet — start by confirming it with a test.
Tannins a musty, earthy smell · a yellow, tea-colored tint · an earthy, musty taste · a colored tint in the glass
Organic matter leached from decaying leaves and peat that tints water yellow or tea-colored with a musty edge. Harmless but stubborn to remove.
Confirm with a test → We don't have a dedicated fix guide for this yet — start by confirming it with a test.
Sediment cloudy or gritty water · water that stays cloudy in the glass · falling water pressure
Loose sand, silt, clay, and rust flakes that make water look cloudy or feel gritty, clog downstream filters, and wear out appliances if not caught first.
Confirm with a test → We don't have a dedicated fix guide for this yet — start by confirming it with a test.
Acidic water (low pH) blue-green staining on copper · a metallic taste · corroded fittings · pinhole leaks in copper
Acidic well water that corrodes pipes, leaves blue-green stains on copper, and can leach copper and lead. Usually neutralized before other treatment.
Confirm with a test → We don't have a dedicated fix guide for this yet — start by confirming it with a test.
High TDS / salinity a salty taste · a bitter or soapy taste
A high combined load of dissolved minerals and salts that can taste salty or metallic. The number alone doesn't say which contaminants are present — a test breaks it down.
Confirm with a test → We don't have a dedicated fix guide for this yet — start by confirming it with a test.
Can't be seen, smelled, or tasted — rule these out with a test
Some of the most serious contaminants give no warning signs at all. A test is the only way to know.
- Arsenic. A naturally occurring, tasteless and odorless toxic element found in some wells. There's no color or smell to warn you — only a lab test detects it. The EPA limit is 10 ppb. See the fix →
- Nitrate. A dissolved contaminant from fertilizer, septic systems, and animal waste — especially dangerous to infants. No taste or smell; the EPA limit is 10 ppm.
- Coliform bacteria. Indicator bacteria whose presence means surface contamination has reached your well and other germs may be there too. No taste or smell; confirmed only by a lab test.
Ask the lab to test for these
- Coliform bacteria
- Nitrate
- pH
- Hardness
- Iron
- Manganese
- Total dissolved solids (TDS)
City water
Answer a few questions about what you see, smell, and taste at the tap, and we'll point you to the likely cause — and to the free report and tap test that confirm it.
Match what you're seeing, smelling, or tasting
Chlorine or chloramine a chlorine or pool smell
The disinfectant your utility adds on purpose to keep the water safe all the way to your tap. It's doing its job, but it can leave a swimming-pool taste or smell. A carbon filter removes it — check your CCR first to see whether your utility uses plain chlorine or chloramine, because chloramine needs a catalytic-carbon filter to take out.
Confirm with a test → We don't have a dedicated fix guide for this yet — start with your CCR and a tap test to confirm it.
Hardness a bitter or soapy feel · white, chalky scale · scale buildup and spotting · short appliance life
Dissolved calcium and magnesium that leaves chalky scale, spots on glasses, and poor lather. City water can be just as hard as well water — hardness is rarely listed on the CCR, so a quick home test is the only way to know your number. Treated with a softener or a salt-free conditioner.
Copper (from your pipes) a metallic taste · blue-green staining · corrosion staining
Blue-green stains on sinks and fixtures usually mean copper is leaching from your home's own pipes, often where the water is a little corrosive. The plant's water is fine leaving the treatment works — this happens on the way through your plumbing, so a tap test is what catches it.
Confirm with a test → We don't have a dedicated fix guide for this yet — start with your CCR and a tap test to confirm it.
Rust or discoloration a metallic taste · orange or brown discoloration · brown or rusty water · occasional discoloration
Orange, brown, or yellow water on a city supply is usually rust stirred up from old cast-iron mains — often right after a water-main break or hydrant flushing nearby. It typically clears on its own in a day or two. If it keeps coming back, it's worth reporting to your utility and running a tap test.
Confirm with a test → We don't have a dedicated fix guide for this yet — start with your CCR and a tap test to confirm it.
Sediment water that stays cloudy
Grit or persistent cloudiness that doesn't clear as it sits. On municipal water it's usually knocked loose by main work upstream; a simple sediment pre-filter at your point of entry catches it if it's a recurring problem.
Confirm with a test → We don't have a dedicated fix guide for this yet — start with your CCR and a tap test to confirm it.
Taste & odor (earthy or musty) an earthy or musty taste
An earthy, musty, or fishy taste on city water is most often a seasonal algae bloom at the source — the compounds behind it (geosmin and MIB) are harmless but hard to miss. A carbon filter clears the taste; the water itself is still within limits.
Confirm with a test → We don't have a dedicated fix guide for this yet — start with your CCR and a tap test to confirm it.
Your report and pipes can hide these — confirm with a tap test
A utility can meet every EPA limit at the plant and you can still have lead from your own pipes or PFAS that wasn't reported. These give no warning signs — a test at your tap is the only way to know.
- Lead. Tasteless, colorless, and dangerous — especially for infants and during pregnancy. Lead almost never comes from the treatment plant; it dissolves in from lead service lines, old solder, and brass fixtures inside your own home. Your CCR can't see your plumbing, so the only way to know is a test drawn at your tap. There is no safe level.
- PFAS (“forever chemicals”). A family of industrial chemicals that don't break down and have been found in many public supplies. They have no taste or smell, and older CCRs often didn't report them. The EPA set enforceable limits in 2024 — a certified lab test tells you where your tap stands, and a reverse-osmosis or PFAS-rated filter removes them.
- Disinfection byproducts. Trace compounds (trihalomethanes and haloacetic acids) that form when the disinfectant reacts with natural organic matter in the water. Your CCR lists them, so it's the fastest place to check — if they run high near the limit, a carbon filter reduces them at the tap.
Confirm it in two steps
- Your utility's report (CCR) — start here
- Lead & copper, drawn at your tap
- Hardness (test at home)
Just better drinking water
Answer a few quick questions about your kitchen and what you want, and we'll point you to the type of filter that fits — under-sink RO, countertop RO, carbon, or a faucet or pitcher filter.
The four types of drinking-water filter
Under-sink reverse osmosis The most thorough — its own little faucet under the sink
Pushes your water through a membrane that pulls out the widest range of what you can't taste or see — lead, PFAS, nitrate, arsenic, and most dissolved solids — then sends it to a dedicated little faucet at the sink. It's the deepest drinking-water filtration you can put in a home kitchen.
Best for: Broad contaminant removal · Coffee, ice, and cooking · Homeowners
Worth knowing: It ties into your cold-water line and sends a few drops of rinse water down the drain per glass, and it strips the natural minerals along with everything else — most good systems add a remineralizing stage to bring the taste back.
Countertop reverse osmosis RO-level purity with nothing to plumb in
The same reverse-osmosis purity as an under-sink system, in a unit that sits on the counter and plugs into an outlet. There's nothing to drill and nothing to tie into your pipes, and it moves with you when you go — the RO answer for a rental.
Best for: Renters · No installation · Broad contaminant removal
Worth knowing: It takes up counter space and holds a tank of purified water, and like any reverse osmosis it removes the natural minerals along with contaminants.
Under-sink carbon filter Great taste, full flow, keeps the minerals
A carbon block under the sink that takes out chlorine, odors, and many organic compounds while leaving the water's natural minerals in. Water comes through your existing faucet at close to full pressure, so it keeps up with filling pots and cooking.
Best for: Taste and chlorine · High flow · Keeping the minerals
Worth knowing: Carbon is excellent for taste and many chemicals, but it leaves dissolved solids in, and only cartridges certified for lead reduction should be trusted for lead — match the certification to what you actually want gone.
Faucet or pitcher filter The cheapest start, nothing to install
A filter that screws onto your faucet or lives in a pitcher in the fridge. It's the lowest-cost, lowest-commitment way to improve taste, and some models are certified to reduce lead — a sensible first step or a good fit for a rental.
Best for: Lowest cost · Renters · Small households
Worth knowing: The cartridges are small, so they need changing often and can't match a reverse-osmosis or under-sink system on volume or range. Check the certification for anything beyond taste.
Compare all four types side by side
Want the full comparison? Our drinking-water guide lines up reverse osmosis, carbon, and faucet or pitcher filters with certifications and typical prices.
What's your water?
Pick where your water comes from and we'll run the right diagnostic. It takes about 90 seconds, and no email is required.