Short answer: a filter removes what its cartridge is built to capture; a distiller separates the water itself from everything that cannot evaporate with it. That makes distillation broad in scope for dissolved substances — metals, salts, fluoride, nitrate — while a good activated-carbon filter is better at chlorine, taste and volatile compounds, and is far faster and cheaper to run. Neither method covers everything. Below is the comparison with the limits of each stated plainly, because a purification claim is only as good as the exceptions its maker is willing to name.
Two different physical principles
A household filter works by contact. Water is pushed or drawn through a medium — activated carbon, a membrane, an ion-exchange resin — and contaminants are adsorbed, screened out or exchanged. What comes out depends entirely on that medium and on how loaded it already is. A jug filter, an under-sink carbon block and a reverse-osmosis system are three very different devices sharing one everyday word.
A distiller works by changing the state of the water. Water is boiled in a chamber; only vapour rises; the vapour is cooled and condensed into a separate container. Substances that cannot evaporate at that temperature stay behind. This is not a capture process with a finite capacity — it is a phase change, and the residue is visible as scale when you descale the chamber.
The practical consequence: a filter's performance degrades as the cartridge fills, and it fails quietly. A distiller's separation does not degrade with use, but scale slows it down and raises its electricity consumption, which is why descaling matters.
Side by side
| Factor | Carbon filter (jug or block) | Reverse osmosis | Distillation |
|---|---|---|---|
| Chlorine, taste, odour | Its core strength | Yes | Handled by the activated-carbon post-filter |
| Dissolved metals such as lead | Only if the cartridge is certified for it | Substantially reduced | Left behind in the chamber |
| Fluoride, nitrate, sodium, hardness | Generally not | Reduced (NSF/ANSI 58 claims exist) | Left behind in the chamber |
| Bacteria, viruses, protozoa | Only if rated for it | Membrane-dependent | Water is boiled, then condensed |
| Volatile organic compounds | Carbon's strength | Partial | Can carry over with the steam — the reason a carbon post-filter is fitted |
| Tritium | No | No | No — see below |
| Speed | Immediate | Continuous but slow | About 5.5–6 hours per 4-litre batch |
| Running requirements | Cartridge changes on schedule | Membrane changes, plumbing, waste water | Electricity (~0.8 kWh per litre), descaling, carbon sachets |
| Installation | None to moderate | Usually plumbed in | None — it stands on the counter |
| Minerals in the finished water | Mostly retained | Largely removed | Removed |
What the health agencies actually say
The US Centers for Disease Control and Prevention lists distillation as removing parasites, bacteria and viruses, along with “many chemicals” including arsenic, barium, cadmium, chromium, lead, nitrate, sodium, sulfate, calcium and magnesium — and states in the same place that it does not remove some volatile organic compounds, volatile solvents and certain pesticides. That last sentence is the one most marketing copy leaves out, and it is precisely why a distiller needs a carbon stage after condensation.
The University of Nebraska–Lincoln Extension guide to distillation adds fluoride, iron, manganese and hardness to the list of compounds left behind, notes that compounds with boiling points near or below water's will vaporise with the steam unless a further process such as an activated-carbon filter is used, and observes that a well-maintained distiller should last ten to fifteen years.
For fluoride specifically, the Minnesota Department of Health lists it under distillation. We cite that rather than the CDC page, which names fluoride under reverse osmosis instead — a small distinction, but the kind worth getting right.
What neither method does
- “Filtered” is not a specification. Two jugs at the same price can make different claims, and performance drops as the cartridge loads. Read what the manufacturer states the cartridge reduces, look for a certification standard, and replace it on schedule.
- Volatile compounds can travel with the steam. Boiling does not separate substances that evaporate as readily as water. The activated-carbon post-filter exists for exactly this reason, and a distiller sold without one is an incomplete design.
- Neither removes tritium. Tritiated water is chemically water. The US Nuclear Regulatory Commission states that tritium “cannot be filtered out of the water”, and the World Health Organization's own guidelines list tritium as “not possible to remove”. No household device of any kind changes that.
- Boiling alone is not distillation. An open pot reduces microorganisms but concentrates what stays behind. The WHO cautions that excessive boiling can concentrate nitrate, advising that water be heated only until it reaches a rolling boil. The US EPA states plainly that boiling does not remove lead.
- Nothing at home makes chemically contaminated water safe. If a supply is known to be contaminated with chemicals, official guidance is to use an alternative source, not to treat it yourself. Follow your water utility's notices.
Choosing between them
The right answer depends on what is in your water and what the water is for.
- Chlorine taste is your only complaint. A carbon filter is the cheapest and fastest answer, and there is no reason to buy more machine than you need.
- You are concerned about dissolved substances — older plumbing, well water, very hard water, agricultural nitrate. Distillation separates these by physics rather than by capture capacity; reverse osmosis also reduces them substantially, at the cost of plumbing and waste water.
- You need water with no dissolved minerals. Steam irons, humidifiers, CPAP machines (always follow the device manufacturer's instructions), aquariums, battery top-up, plant care, cosmetics and laboratory work. This is distilled water's classic use, and no filter substitutes for it.
- You want to stop buying bottled water. Compare your electricity cost per litre with the shelf price. Our cost calculator does the arithmetic for your own tariff.
- You are worried about a specific contaminant. Start from your utility's published water-quality report, then read what a distiller does and does not remove, contaminant by contaminant.
What a distiller costs to run
A Megahome distiller is rated at 580 W. A 4-litre batch running about 5.75 hours draws roughly 3.3 kWh — about 0.8 kWh per litre. Multiply by your own price per kWh and you have your cost per litre, which you can then set against bottled water. Two practical notes: scale on the heating element raises that figure, so descale with citric acid when it appears, and most owners simply run the cycle overnight, since the cooling fan is audible at roughly the level of a desk fan.
Can you use both?
You already are. A Megahome distiller boils, condenses, and then passes the finished water through an activated-carbon sachet in the nozzle — distillation for the non-volatile substances, carbon for the volatile ones. That pairing is the reason the two technologies are better read as complementary than as rivals. What matters is replacing the carbon sachet on schedule; in our guide to boiling, filtering and distilling when water quality is in doubt we set out a tiered replacement interval for uncertain and known-contaminated source water.
Key takeaways
- A filter captures what its cartridge is rated for. A distiller separates water from everything non-volatile. Different physics, different blind spots.
- Distillation covers dissolved metals, salts, fluoride and nitrate; activated carbon covers chlorine, taste and volatile compounds. A Megahome unit uses both, in that order.
- Distillation is slower and uses electricity; a filter is instant but only as good as its cartridge and its replacement schedule.
- No home method removes tritium, and no home method makes chemically contaminated water safe to drink.
Frequently asked questions
Is distilled water better than filtered water?
Neither is universally better. Distillation separates a broader range of dissolved substances; a carbon filter is faster, cheaper and good at chlorine, taste and volatile compounds. Choose according to what is in your water and what you need the water for.
Does distilled water taste flat?
Some people find it so, because dissolved gases and minerals are gone. Letting it stand in a glass container, or adding mineral drops, restores a fuller taste for those who prefer it.
Do I lose important minerals by drinking distilled water?
Drinking water is a minor contributor to mineral intake compared with food for most people. If you have a specific medical condition or dietary concern, ask a doctor or dietitian rather than a manufacturer.
How much water does a distiller make, and how long does it take?
4 litres per batch in about 5.5–6 hours, fully automatic — the unit switches itself off at the end of the cycle.
Does a distiller need plumbing or a filter change?
No plumbing. It needs an activated-carbon sachet replaced periodically and descaling when scale appears.
