The disinfectant most Australian utilities add to keep water safe on its trip through the pipes. It gives tap water that pool-like taste and smell. The ADWG health value is 5 mg/L; you can usually taste it from about 0.6 mg/L.

Chlorine combined with ammonia. It lasts longer in long pipe networks, so some Australian supplies use it instead of plain chlorine. It's harder to filter: plain activated carbon struggles, catalytic carbon handles it. ADWG health value: 3 mg/L.

The small amount of chlorine or chloramine left in the water when it reaches your tap. It's there on purpose, to stop bacteria regrowing in the pipes, which is why filtering at home (not at the plant) is the norm.

A mineral added to most Australian supplies for dental health. The ADWG limit is 1.5 mg/L and utilities usually target well below that. Standard carbon filters don't touch it; activated alumina does.

How much dissolved calcium and magnesium your water carries, usually shown as mg/L of calcium carbonate. Below about 60 mg/L is generally called soft; the ADWG aesthetic value is 200 mg/L. Hard water leaves scale on taps and kettles.

The chalky white crust hard water leaves on shower screens, kettles and taps. It's the calcium and magnesium dropping out of the water, especially when it's heated.

Everything dissolved in your water added together: minerals, salts and a little of everything else, in mg/L. The ADWG aesthetic value is 600 mg/L. A high TDS reading isn't a safety score; it mostly tells you how mineral-rich the water is.

How acidic or alkaline water is, on a 0 to 14 scale where 7 is neutral. The ADWG range for drinking water is 6.5 to 8.5.

By-products that form when chlorine reacts with natural organic matter in water. The ADWG value for total THMs is 0.25 mg/L. Good carbon-based filters reduce them.

Metals like lead, copper and cadmium. In Australia they mostly come from household plumbing and fittings rather than the treatment plant. The ADWG value for lead is 0.01 mg/L.

Carbon-based chemicals that evaporate easily, a family that includes THMs. Activated carbon is the classic media for reducing them.

Sand, rust and fine particles that come loose from ageing mains and household pipes. It's what turns a white filter cartridge brown.

Tiny plastic fragments found in tap and bottled water around the world. The health picture is still being researched; physical filtration stages reduce fine particles.

The unit Australian water reports use for most things in your water. One mg/L means one milligram of a substance in every litre.

In water, 1 PPM is the same as 1 mg/L. You'll see PPM on hydrogen water bottles (dissolved hydrogen) and on TDS meters.

Micrograms per litre, a thousand times smaller than mg/L. Parts per billion (PPB) means the same thing in water. Used for trace substances.

Nephelometric turbidity units, the measure of how cloudy water looks. The ADWG aesthetic value is 5 NTU.

The Australian Drinking Water Guidelines, published by the NHMRC. They set the health and aesthetic values utilities work to; the states turn them into law.

A health value is the level linked to safety over a lifetime of drinking. An aesthetic value is about taste, smell, look and scaling. Water can pass every health value and still taste of chlorine.

US testing standards used worldwide. 42 covers aesthetic issues like chlorine taste and odour, 53 covers health-related contaminants like lead, and 401 covers emerging contaminants.

"Tested to" means a product was tested against a standard's method. "Certified" means a certification body has certified that finished product and keeps auditing it. Always check which one a brand is claiming, and for what.

The international accreditation standard for testing laboratories. A result from a 17025-accredited lab means the lab's methods have been independently assessed.

Carbon processed to be full of tiny pores, so chemicals stick to its huge surface (adsorption). Great for chlorine taste and odour, VOCs and THMs; weaker on chloramine and does nothing for fluoride. GAC means granular activated carbon.

Activated carbon made from coconut shells, with a fine pore structure suited to drinking water.

Activated carbon compressed into a solid block instead of loose granules. Water is forced through tighter paths, so it also strains out fine particles.

Activated carbon with an altered surface that speeds up the breakdown of chloramine, not just chlorine. It's the reason a filter can claim chloramine reduction.

A high-purity copper-zinc blend that reduces chlorine and dissolved heavy metals through a redox reaction. It keeps working in hot water, which is why it's a shower filter favourite.

A different copper-zinc blend aimed at iron and hydrogen sulfide (the rotten-egg smell), more common in bore water systems than in city showers.

A porous aluminium oxide media that adsorbs fluoride. It's what lets a gravity filter reduce fluoride without reverse osmosis.

A fine-pored ceramic element that physically blocks particles. In Trinity, the ceramic stage acts as a sub-micron barrier for rust, sediment and fine particles.

Beads that swap one dissolved ion for another, for example calcium for sodium in a water softener. Used in some filters to target specific metals.

Uses ascorbic acid to neutralise chlorine and chloramine, usually in shower filters. The vitamin C is used up as it works.

Pushes water through a very fine membrane under pressure. It strips almost everything, including the minerals, and sends part of the water down the drain.

Adding calcium and magnesium back after filtering, for a smoother taste. Trinity's mineral stage does this and can lift pH by up to +2.0.

A filter that stacks different media in sequence, each doing a different job. One media can't cover chlorine, chloramine, fluoride, metals and particles on its own.

The size of particle a filter stage can stop. One micron is a thousandth of a millimetre; sub-micron means smaller than that.

How long water spends touching the media. More contact time generally means more reduction, which is why slow gravity filters can do more than a fast pass through a tap filter.

How much water comes through per minute. Shower filters are built to keep a strong flow; if it drops over time, the cartridge is usually due.

How long a cartridge works before the media is spent. It depends on your water and how much you use: a Trinity cartridge lasts 6 to 12 months, a shower cartridge about 6 months for a couple and 3 months for a family of 4.

You pour water in the top and gravity pulls it through the cartridges into a lower tank. No plumbing, no power and no wastewater. Trinity is one.

A filter that sits on the kitchen bench instead of being plumbed in. Renter friendly and moves house with you.

A filter that screws onto your kitchen tap and filters on demand, like Tap Mate.

A compact filter that fits between the shower arm and your existing shower head, like Shower Mate.

A shower head with the filter built in, which replaces your old head. Shower Max and Shower Mate Plus+ work this way.

The standard thread on most Australian shower arms. Check for it and most shower filters fit by hand, no plumber needed.

A tough, heat-resistant glass also used in lab glassware. The Hydronizer bottles, the Pitcher and the Glass Trinity tanks are borosilicate.

A common food-grade stainless steel used for water fittings and housings.

Hydrogen gas dissolved in water. It's tasteless and slowly escapes once the water is made, so fresh is best.

Running a small current through water to split it into hydrogen and oxygen. Every hydrogen bottle uses it; what matters is how the gases are kept apart.

Solid polymer electrolyte / proton exchange membrane. A membrane separates the hydrogen side from the oxygen side, so hydrogen goes into your water and excess oxygen is released into the air. The Hydronizer range uses SPE/PEM with platinum-coated titanium plates.

A millivolt reading of whether water tends to give or take electrons. Hydrogen water reads negative, but ORP is indirect; PPM is the direct measure of dissolved hydrogen.

How much hydrogen is dissolved, in parts per million. Hydronizer Classic reaches 2.4 PPM, Pro 5 PPM and Infinity 10 PPM; the Pitcher makes 1.8 to 2.4 PPM.

Water with a pH above 7, usually from added minerals or a stick in the bottle. It's a different thing to hydrogen water.

A loose label used for hydrogen bottles, basic electrolysis bottles and alkaline mineral bottles alike. Judge a bottle by its tested PPM, not the word on the box.