Apr 22 , 2026
Everpure H-300 Water Filter: Complete Guide and Replacement
The Everpure H-300 is one of the most recognized under-sink drinking water filters in the country, and there is a reason it shows up in restaurants, offices, and serious home installations. It delivers commercial-grade filtration from a cartridge that fits under a residential kitchen sink. If you have one in your home, or you are deciding whether the H-300 is the right upgrade, this guide covers what you actually need to know.
What the H-300 Does
The Everpure H-300 uses a proprietary precoat filtration technology. Inside the cartridge, a layer of specialized media is deposited on a filter surface, creating a very fine barrier that captures contaminants as water passes through. The design is more sophisticated than a standard carbon block filter and is one of the reasons the H-300 has been the benchmark for premium under-sink drinking water filtration for decades.
Specifically, the H-300 reduces:
- Chlorine taste and odor
- Cysts (Cryptosporidium and Giardia) down to 99.95 percent
- Particulates and sediment down to 0.5 microns
- Dirt, rust, and oxidized iron particles
- Lead (in select rated configurations)
- Mold, algae, and microorganisms at the filter level
It does not remove fluoride, nitrates, TDS (total dissolved solids), or specific dissolved chemical contaminants. For those, reverse osmosis systems address a different problem category.
Capacity and Lifespan
The H-300 is rated for 300 gallons of filtered water or 6 months of typical residential use, whichever comes first. In practice, most households use their water filter well under the 300-gallon rating in 6 months, so the time-based replacement is the more common trigger.
A few signals that the cartridge is at end of life:
- Flow rate noticeably slowing at the filtered faucet
- Chlorine taste returning
- Any cloudiness or off taste in filtered water
- Six months have passed since install, regardless of flow
Replacing on schedule matters. A cartridge past its rated capacity stops filtering effectively and can release captured contaminants back into the water stream.
How to Identify the H-300 in Your System
The H-300 cartridge is a white cylinder with blue cap graphics. The cartridge itself does not thread in. It locks into an Everpure housing with a quick quarter-turn connection. If your system has the H-300, the housing on the wall or cabinet will have the Everpure logo and a model designation starting with EV.
Systems that use the H-300 cartridge include:
- Everpure H-300 (single-cartridge system)
- Everpure H-300 NXT (current production version, same cartridge)
- Several Everpure drinking water systems built around this cartridge body
If you are looking at an older installation and not sure, a photo of the housing shape is usually enough to confirm. Our support team can identify a system from a photo and confirm the right replacement cartridge.
Replacement Installation (Step by Step)
Replacing an H-300 cartridge takes about 90 seconds when you know the steps.
Step 1. Turn off the water supply to the filter. Most installations have a shutoff valve on the cold water line feeding the system. Close it fully.
Step 2. Open the filtered-water faucet to release pressure. A small amount of water will drain. Close the faucet when flow stops.
Step 3. Turn the old cartridge about one-quarter turn counterclockwise. The cartridge unlocks and drops down. Set it aside to drain into a sink or bucket.
Step 4. Take the new cartridge out of the package. Check the O-ring on top is seated correctly. Do not lubricate.
Step 5. Align the new cartridge with the housing head. Push up and turn clockwise about one-quarter turn until it stops. The cartridge is now locked in.
Step 6. Open the water supply slowly. Check for leaks at the head seal.
Step 7. Flush the new cartridge by running the filtered-water faucet for 5 minutes before drinking. This removes any loose carbon fines from the new media.
Step 8. Note the date somewhere visible (the cartridge body, the housing, or a calendar reminder). Six months from this date is the next replacement target.
Compatibility Notes
The H-300 cartridge fits every Everpure system designed for it. It does not fit H-54, H-104, or H-1200 systems, which use different cartridges with different housings. If you are unsure which cartridge fits your system, the model number on the housing head is the fastest way to confirm. Our phone support (855-789-FAST) or the model-lookup tool on the product page will identify the right cartridge.
Third-party aftermarket cartridges are sold that claim H-300 compatibility. Some are acceptable. Most do not deliver the same filtration performance because the precoat technology is proprietary to Everpure and not easily duplicated. For a premium system, an authentic Everpure cartridge is almost always the right call.
What It Costs
Authentic Everpure H-300 cartridges run $90 to $130 depending on retailer and packaging (single vs multi-pack). Buying direct from a specialist filter retailer typically beats big-box pricing by 15 to 30 percent.
On a cost-per-gallon basis, the H-300 runs roughly $0.30 to $0.40 per gallon of filtered water over the cartridge life. Compare that to bottled water at $1.00 to $2.00 per gallon equivalent, and the math is clear for a household using the system regularly.
Buying a Replacement H-300
Water Filters FAST stocks authentic Everpure H-300 cartridges with same-day shipping on weekday orders placed before 1pm Central. Free shipping over $75. If you order before the morning cutoff, the cartridge typically arrives in 1 to 3 business days depending on your location.
Every filter on the site comes with our satisfaction guarantee and 30-day returns. If the cartridge you receive is the wrong fit for your system or anything else is off, we handle it.
Frequently Asked Questions
How long does an Everpure H-300 filter last? 300 gallons of filtered water or 6 months, whichever comes first. Most residential installations hit the 6-month mark before the gallon rating.
Can I use a generic aftermarket cartridge in my Everpure H-300 system? Technically yes, many aftermarket cartridges fit the housing. Performance varies. The H-300 precoat technology is proprietary to Everpure, so aftermarket cartridges that fit the housing do not necessarily match the filtration rating. For most households, the authentic Everpure cartridge is worth the small price difference.
Does the Everpure H-300 remove fluoride? No. The H-300 is not rated for fluoride reduction. For fluoride removal, a reverse osmosis system is the typical solution.
What is the difference between the H-300 and the H-300 NXT? The NXT is the current production version of the system. It uses the same cartridge body and specifications. If you have an older H-300 system, the same replacement cartridge works.
How do I know when to replace my H-300 cartridge? Six months from installation, 300 gallons of use, or sooner if flow rate slows noticeably, chlorine taste returns, or water appears off in any way. Replace on whichever comes first.
Where can I buy an authentic Everpure H-300 filter with fast shipping? Water Filters FAST carries authentic H-300 cartridges with same-day shipping on weekday orders placed before 1pm Central. Free shipping over $75, satisfaction guarantee, and 30-day returns.
