Charcoal Water Filter: Are They the Same as Carbon Filters?

If you've ever used a Brita pitcher, a fridge filter, or a countertop charcoal stick, you've already used a carbon filter. Charcoal and carbon are the same material. The difference is how they're processed and how much filtration they can actually deliver.

People who call me about a whole house carbon tank usually call it "the charcoal filter." Below is what "activated" means, whether grill charcoal filters water, coconut shell or coal, and when a pitcher stops being enough.

Charcoal vs Carbon: Are They the Same Thing?

Yes. A charcoal water filter and a carbon water filter use the same base material. Charcoal is carbon. When you burn wood, coconut shells, or coal without enough oxygen, the result is charcoal, which is mostly carbon.

The water treatment industry calls it "carbon" or "activated carbon." One caller in South Florida, pricing our 2.5 tank, put it simply: "I just need the charcoal." The University of Georgia's extension guide uses both words: activated carbon is "also called activated charcoal." But the filtering mechanism is identical: water passes through a porous carbon material, and contaminants stick to the surface through a process called adsorption.

The real question isn't whether charcoal and carbon are different. They're not. The real question is: what kind of carbon, and how much of it?

What makes charcoal a water filter

Grill or campfire charcoal is not the charcoal in a water filter, because it has not been activated. Activated carbon starts from coal, wood, coconut shell or nutshells, and is heated with steam to about 2300°F without oxygen. That opens up a huge number of tiny pores. One ounce of activated carbon can have about 30,000 square yards of surface, about five times the size of a football field. That surface is where organic chemicals stick and where chlorine is broken down.

How activation and adsorption work, step by step, is in my guide to what activated carbon is.

Can regular charcoal filter water?

Not the way a carbon filter does. Kingsford describes its briquets as wood that is carbonized, blended with natural binders and pressed, and there is no steam activation step in that. If you want carbon in your water, use activated carbon that is sold for water.

Carbon from coconut shells or coal

Coconut shell carbon is good activated carbon, but standard coconut shell carbon does not have the catalytic activity for chloramine and hydrogen sulfide. Every whole house carbon tank we sell ships with Centaur, a catalytic carbon that Calgon Carbon makes from bituminous coal for those two. Nebraska Extension puts it this way: the source of the carbon and the activation method decide what it removes.

Pitcher Charcoal Filter vs Whole House Carbon Filter

A pitcher and a whole house tank use the same material. What differs is how much carbon, which grade, and how many taps it reaches. A Brita Original filter is rated for 40 gallons, about 2 months. The 2.5 cubic feet of Centaur carbon in our Clack 2.5 tank, two 1 cubic foot bags and one 1/2 cubic foot bag of it, treats every tap in the house for 4 to 5 years in most homes.

The middle option is a carbon cartridge on the main line. Our 20 inch Big Blue carbon kit takes the chlorine taste and smell out of every tap, and the cartridge is changed every 3 to 6 months. It uses standard granular carbon, which removes chloramine slowly and incompletely, so it is not the one for a city that uses chloramine.

People ask me why they need a whole house carbon tank when they can just use a pitcher. What I tell them: "when you have high levels of chlorine in your water and chlorine byproducts, you wanna filter every faucet, every fixture in the house." A pitcher only reaches the water you pour from it; the shower and every other tap still get chlorinated water.

When a pitcher is not enough

• You want every tap filtered. A pitcher filters what you drink. If chlorine bothers you in the shower, the filter has to be on the main line.
• Your city uses chloramine. Standard carbon takes chloramine out slowly. A catalytic carbon like Centaur is made for it. Here is how to test for chloramine at the tap.
• Your well water smells like rotten eggs. That smell is hydrogen sulfide. A catalytic carbon tank handles an average smell; a strong one needs a sulfur filter. A lab test tells you how much you have; our well water test is $199.
• You rent. If you can't install anything, a pitcher, a shower head filter and a single faucet filter are the right answer.

Pitcher or a whole house tank?

Text me your water source

Tell Aidan whether you're on city water or a well, and what you notice: a chlorine smell, a rotten egg smell, a taste. He'll tell you whether a pitcher is enough or which carbon tank fits your house.

Text Aidan443-277-2204 Call800-460-5810Aidan

8 AM to 5 PM Eastern, seven days a week. A real person, not a call center.

Where the carbon filter tank goes

On a well, the carbon tank goes after the iron filter and the softener. The UV light goes after it, last. When a well owner asked me where a charcoal filter would go, my answer was: "we would put that after the softener and before the UV. So the UV would be last."

1. Pressure tank
2. Sediment filter
3. Iron filter or acid neutralizer, if you need one
4. Water softener, if you need one
5. Carbon tank, if you want one
6. UV light, last

The reasons for that order are in the correct order for well water treatment.

On city water it is the other way around: the carbon tank goes first and the softener second, because chlorine shortens the life of softener resin. More on that pairing is in a carbon tank with a softener, and we sell the two as a package starting at $3,195.

For most homes I recommend the non-backwashing tank. A backwashing tank needs a drain and electricity. When another well owner asked which one, my answer was: "Non-backwashing. You don't really need the backwashing." When backwashing is worth it is in my guide to the backwashing or non-backwashing carbon filter, and my picks for which carbon tank fits your water name the tank for each house.

What comes with the carbon filter tank

The tank ships empty. With our Clack 2.5 you get the tank, the Clack head with the parts to put it on the tank, a bypass valve, a fill funnel and 2.5 cubic feet of Centaur carbon in two 1 cubic foot bags and one 1/2 cubic foot bag. The carbon is poured in through the funnel at install. Plumbing fittings are not included. There is no drain line to run and nothing to plug in.

I recommend having a plumber put it in. There is no drain line and no electricity, just an inlet and an outlet on the cold water main, so it is about an hour or two of a plumber's time, and I'm a phone call away for your plumber at 800-460-5810. If you have done some plumbing and would rather do it yourself, text me at 443-277-2204 with any questions.

When the water comes back on, run it for 10 to 15 minutes. One owner called me right after his new system went in because the water had a charcoal taste, and I told him: "That's the carbon. You gotta run the water for like 10, 15 minutes." The first water can come out dark, and you might see a little black carbon in the toilets. Don't get alarmed.

Every 4 to 5 years the old carbon is dumped and two new 1 cubic foot bags and a half bag go in; Centaur is $295 a cubic foot. I tell people to put a sticker on the tank with the install date, then change it out 5 years from that date.

Frequently asked questions