How to Clean Your ZeroWater Pitcher, Dispenser & Filter | Culligan

Updated May 2026 — Now covers both Legacy ZeroWater and new Culligan with ZeroWater Technology devices.

If your filtered water suddenly tastes off — sour, fishy, or flat — it's almost always a sign that your filter needs replacing and your pitcher or dispenser is due for a quick clean. Whether you have a Legacy ZeroWater device or one of the new Culligan with ZeroWater Technology pitchers and dispensers, this guide covers everything: how to identify your device, step-by-step installation, cleaning instructions, TDS meter use, and troubleshooting. Shop replacement filters when you're ready to restock.

Which device do you have? Legacy ZeroWater vs. Culligan with ZeroWater Technology

Before you clean or replace anything, confirm which product line you own — the filters are not interchangeable and they install differently.

What you'll need before you start

Gather these items before disassembling your device:

• TDS meter (included with your device)
• Mild dish soap
• Bowl of warm water
• Soft cleaning sponge or cloth
• Paper towels
• Clean, flat surface to reassemble on
• One new replacement filter (if you're also doing a filter change)

How to install your ZeroWater filter

This section covers filter installation for both product lines. If you're only cleaning the device (not replacing the filter), skip to the next section.

Legacy ZeroWater — bottom-threaded installation

1. Remove the old filter by twisting it counterclockwise from the bottom of the reservoir.
2. Dispose of the used filter — check ZeroWater's recycling program or your local municipality's program.
3. Align the new filter with the opening at the bottom of the reservoir.
4. Twist the filter clockwise until snug and sealed. Do not over-tighten.
5. Reattach the reservoir to the pitcher or dispenser body.
6. Fill the reservoir with cold tap water and let it filter through completely into the lower chamber.
7. Pour filtered water into a glass and test with your TDS meter. Target reading: 000 ppm. If the reading is above 006 ppm, remove the filter, check for cross-threading, and re-seat it.

Culligan with ZeroWater Technology — top-threaded installation (new)

1. Twist and lift the old filter straight up from the top of the reservoir.
2. Dispose of the used filter responsibly.
3. Take your new Culligan with ZeroWater Technology filter and lower it straight down into the reservoir from the top.
4. Twist the filter to lock it into the seated position.
5. Reattach the reservoir and fill with cold tap water. Allow the water to filter fully into the lower chamber.
6. Test with your TDS meter — target reading is 000 ppm. Readings above 006 ppm mean the filter isn't fully seated. Remove and reseat it.

Pro tip: Always use cold tap water. Hot water can damage the filter media and reduce filtration performance.

How to clean your ZeroWater pitcher or dispenser

The cleaning process is the same for both product lines. Always clean your device whenever you replace the filter, or any time you notice odor, visible buildup, or the device has been stored empty for more than a week.

Legacy ZeroWater

1. Pour out all remaining water from both the reservoir and the lower chamber.
2. Remove the filter by twisting counterclockwise from the bottom of the reservoir. Set it aside if it's still usable — check your TDS reading to confirm.
3. Lift the upper reservoir out of the pitcher or dispenser body and fully disassemble.
4. Wash all plastic parts — lid, reservoir, and pitcher or dispenser body — with a soft sponge and mild dish soap in warm water.
5. Rinse all parts thoroughly for at least 30 seconds until no soap residue remains.
6. Dry completely with a clean paper towel. Do not reassemble with any moisture remaining.
7. Reinstall the filter and run a TDS check before drinking.

Culligan with ZeroWater Technology (new)

1. Twist and lift the filter straight up from the top of the reservoir and set it aside.
2. Disassemble fully — sliding lid, reservoir, and dispenser or pitcher body.
3. Wash all plastic components with mild dish soap and warm water. Use a soft sponge — no abrasive scrubbers.
4. Rinse all parts thoroughly and dry completely with a paper towel.
5. Do not put any components in the dishwasher — dishwasher heat can warp plastic parts and compromise the seal.
6. Re-seat the top-load filter firmly before filling with water.

How often should you clean your device?

• Every 2–4 weeks as a general rule
• Always clean when you change your filter
• Clean immediately if you notice odor, visible residue, or the device has been stored empty for 7+ days

How to remove and use the TDS meter

Your TDS (total dissolved solids) meter is your most important maintenance tool. It tells you whether your filter is working and when it needs to be replaced.

To remove the TDS meter: The meter slides into a slot on the exterior of the pitcher or dispenser. Pull it straight out — no twisting needed. Rinse it under cold water before and after each use. Do not fully submerge the meter in water.

How to read your TDS results:

• 000 ppm — filter is working correctly and fully seated
• 001–006 ppm — acceptable tolerance range, filter is functioning
• 006+ ppm — filter is near or at end of life, or is not properly seated. Re-seat or replace.

To understand what TDS means for your water quality and health, visit our guide: What is TDS and what level is safe to drink?

When to replace vs. when to just clean

Cleaning the pitcher body keeps your device hygienic and extends its life. But a clean pitcher cannot fix an exhausted filter — those need to be replaced.

Replace your filter when:

• Your TDS meter reads above 006 ppm after filtering
• The water has a noticeable fishy, sour, or acidic taste
• You have reached the filter's rated gallon capacity (Legacy: ~15 gal / Culligan with ZeroWater Technology: ~20 gal)
• The filter has been sitting unused in the device for an extended period

Your actual filter life depends on how much water your household consumes and your tap water's starting TDS level. Higher TDS tap water — common in areas with hard water or older pipes — will exhaust filters faster. Test regularly and keep a spare filter on hand. For a full guide on when and how often to replace your filter, see: When to change your ZeroWater filter.

Troubleshooting common ZeroWater issues

Filter smells or tastes like fish

A fishy or ammonia-like smell from filtered water is caused by sulfur compounds in high-TDS tap water reacting with the ion-exchange resin in the filter. It typically signals the filter is near the end of its life. Replace the filter when TDS reads 006+. Going forward, avoid leaving a partially used filter out of the device for extended periods.

Water tastes sour or acidic

A sour or acidic taste usually means the filter is exhausted. As the ion-exchange resin reaches capacity, it releases hydrogen ions into the water. Test with your TDS meter — if the reading exceeds 006 ppm, replace the filter.

Water is filtering very slowly or not draining

Slow filtration is most often caused by a clogged or near-exhausted filter — the filter media has trapped its maximum load of dissolved solids. This is most common in areas with very high TDS tap water. Check your TDS reading: if it's close to or above 006, replace the filter. If slow flow continues with a new filter, check that the filter is fully seated and that there is no debris blocking the reservoir opening. Note: ZeroWater's 5-stage filtration is inherently slower than 2-stage competitor filters — some slowdown is normal and expected.

TDS reading is above 006 ppm with a brand new filter

This almost always means the filter is not properly sealed. Remove it, inspect for cross-threading or debris, and re-seat it carefully. If the reading remains high after reseating, contact Culligan customer support.

Not sure if your filter is the right one for your device? Check our filter compatibility guide.

Why ZeroWater's 5-stage filtration needs regular maintenance

Both Legacy ZeroWater and Culligan with ZeroWater Technology filters use a 5-stage filtration system designed to remove 99.9% of total dissolved solids (TDS). Because each stage is doing active work on your water, the filter media exhausts over time — which is why regular cleaning and timely filter replacement matter.

The five stages are:

1. Coarse mesh filter screen — removes fine particles and sediment
2. Foam distributor layer — reduces suspended solids
3. Activated carbon + oxidation reduction — removes organic contaminants and prevents bacterial growth within the filter
4. Ion-exchange resin — removes inorganic compounds, metals, and nonmetals
5. Ultra-fine mesh screen — catches any remaining fine particles before water exits the filter

The new Culligan with ZeroWater Technology filter carries expanded certifications to reduce Total PFAS (forever chemicals), pharmaceuticals, and pesticides — contaminants not covered by the Legacy filter. Both lines are also certified to reduce lead. Learn more about our 5-stage water filter pitcher lineup.

Frequently asked questions

Can I clean my ZeroWater filter itself?

No. The filter media — ion-exchange resin and activated carbon — cannot be rinsed or cleaned. Once the filter is exhausted (TDS reads 006+), it must be replaced. Only the pitcher body, lid, and reservoir are washable.

Are Legacy ZeroWater and Culligan with ZeroWater Technology filters interchangeable?

No. Culligan with ZeroWater Technology filters use a top-threaded design and are not compatible with older Legacy ZeroWater pitchers and dispensers, which use a bottom-threaded filter. Always match your filter to your device generation. If you see the Culligan logo and a sliding lid on your device, you have a UMC device and need the top-load filter. See our full filter compatibility guide if you're unsure which filter fits your device.

How do I replace a ZeroWater filter?

For Legacy devices, untwist the old filter counterclockwise from the bottom of the reservoir, then twist the new filter in clockwise until snug. For Culligan with ZeroWater Technology devices, twist and lift the old filter straight up and drop the new one straight down from the top. Run a TDS check after — target reading is 000 ppm. Full step-by-step instructions are in the installation section above.

How do I remove the TDS meter from my Culligan pitcher?

The TDS meter slides into an exterior slot on the pitcher or dispenser. Pull it straight out — no twisting required. Rinse under cold water before and after use. Do not fully submerge the meter.

Why is my ZeroWater filter not draining or filtering slowly?

Usually means the filter is near the end of its life or is not fully seated. Check your TDS reading — if it's above 006, replace the filter. Also clean the upper reservoir to remove any sediment buildup. Note that 5-stage filtration is naturally slower than 2-stage systems.

Why does my ZeroWater filter smell like fish or taste sour?

Both symptoms typically mean the filter is exhausted or has been sitting unused. A fishy smell is caused by sulfur compounds in high-TDS tap water reacting with the ion-exchange resin. A sour taste means the resin is releasing hydrogen ions as it reaches capacity. In both cases: test with your TDS meter and replace the filter if reading exceeds 006 ppm.

Can I put my ZeroWater pitcher in the dishwasher?

Hand washing only. Dishwasher heat can warp the plastic components and affect the seal between the reservoir and the pitcher or dispenser body, which can cause leaks and poor filtration performance.

Does Culligan with ZeroWater Technology remove PFAS?

Yes — the Culligan with ZeroWater Technology filter is certified to reduce Total PFAS (forever chemicals). The Legacy ZeroWater filter is certified to reduce PFOA and PFOS specifically. For more detail on PFAS in drinking water, visit our PFAS water filter guide.

How often should I replace my Culligan ZeroWater filter?

Replace your filter when your TDS meter reads above 006 ppm — not on a fixed schedule. Filter life varies by household water consumption and your tap water's starting TDS level. Legacy filters last up to ~15 gallons; Culligan with ZeroWater Technology filters last up to ~20 gallons. For a detailed breakdown by TDS range, see our guide: When to change your ZeroWater filter.

What TDS level should my filtered water be?

The target for ZeroWater-filtered water is 000 ppm. Readings of 001–006 ppm are within acceptable tolerance. Anything above 006 ppm means the filter needs to be replaced or reseated.

Ready for a fresh filter?

Keeping a spare filter on hand means you're never caught without clean water. Whether you have a Legacy ZeroWater device or the new Culligan with ZeroWater Technology pitcher or dispenser, replacement filters are available individually or in money-saving multipacks with Subscribe & Save.

Shop Culligan with ZeroWater Technology replacement filters →