Why your tap water tastes of chlorine
Melbourne's mains water is disinfected with chlorine, and the taste and smell you notice at the tap is that chlorine doing its job on the way to your house. It is not a fault and it is not a health problem, and it can be removed entirely with a carbon filter.
Why it is stronger some days than others
Chlorine taste is strongest in warm weather, at the start of a hot spell, and in houses at the end of a supply run, because warmer water holds chlorine differently and the dose is set so there is still some left at the furthest tap.
Summer heat speeds up the chemical reactions that make chlorine's smell noticeable, which is why a glass of water can taste stronger in January than in July from the exact same supply. A house at the far end of a street, or the end of a long dead-end main, gets water that has travelled further and sat longer, and the retailer's dosing has to allow for that distance. Your neighbour closer to the main feed may genuinely taste less of it. A change in taste right after mains work nearby is also normal: repairs and flushing can temporarily shift the dose or the flow direction on your street.
The cheapest things to try first
A jug of water left uncovered in the fridge for an hour loses most of its chlorine smell for free, and that is worth trying before you buy anything.
Chlorine is volatile, so leaving water open to the air lets a good share of it evaporate off before you drink it. A basic filter jug does the same job faster, at a real ongoing cost: replacement cartridges typically work out to somewhere between ten and thirty cents a litre over a year, once you account for how often they need changing. The honest limitation is what a jug does not touch. It filters what you pour into it and nothing else, so the shower still smells of chlorine, the kettle still fills from an unfiltered tap, the washing machine draws mains water directly, and the hot water system gets no benefit at all. That gap, not the taste of drinking water alone, is usually the actual reason people move past a jug.
What actually removes it
Activated carbon removes chlorine, and a coconut carbon block on the main line removes it from every tap in the house rather than one.
Carbon works by adsorption: chlorine molecules bind to the surface of the carbon as water passes through it, rather than being filtered out by size the way sediment is. A solid carbon block forces water through the entire density of the material, which gives it more contact time and a more complete result than loose granular carbon in the same size housing. The sediment stages ahead of it exist largely to protect the carbon: catching grit and rust first means the carbon block is not doing double duty and lasts its full rated life instead of clogging early. Carbon does have a working life. It keeps adsorbing chlorine until its surface is used up, which is the entire reason cartridges are rated and changed on a twelve month cycle rather than left in indefinitely.
Every tap, or one tap
A filter on the main line treats the shower, the kettle and the laundry as well as the kitchen tap, and a filter under the sink treats one outlet. Whole house filter or under sink filter? sets out which one solves which problem.
What it costs
A three-stage whole-house filter installed by a licensed plumber is $2,990 fixed with Every Tap, and published Melbourne prices elsewhere run $2,990 to $3,300.
| Package | For | Installed price |
|---|---|---|
| Fresh Tap | Whole house, every tap | $2,990 |
| Pure Only | Reverse osmosis, under the sink | $1,490 |