Add a tap aerator at the bathroom basin
A few-euro aerator screws onto the end of your tap and blends air into the stream — so it still feels full while pushing far less water through every wash, shave and toothbrush rinse.
The water that pours from a basin tap is mostly wasted. You’re rinsing a toothbrush, wetting your hands or filling a glass — none of which needs the ten-plus litres a minute many taps deliver. An aerator is the small mesh-and-housing piece on the end of the spout that you can swap for a low-flow version, and it solves this without any change to how you use the tap.
It works by pulling air into the water as it leaves the spout. The stream stays soft and full to the touch and looks completely normal, but you’re getting a blend of air and water rather than a solid column — so far fewer actual litres go down the drain. Because so much basin water is hot, you’re also cutting the energy spent heating water you never really needed, which is where a chunk of the saving quietly hides.
The realistic caveats are minor. Threads come in a few sizes, so the only fiddly bit is matching the part — take the old one with you or buy a small assorted kit and you’re sorted. And aerators collect limescale, especially in hard-water regions, so a rinse every few months keeps the flow honest. For a couple of euros and ten minutes, it’s about the cheapest water-and-energy fix in the house, and once it’s on you’ll genuinely forget it’s there.
How to do it
- Unscrew the existing nozzle from the tap spout (turn anticlockwise as you look up at it — fingers usually do it, or wrap a cloth round it and use pliers gently).
- Check the thread: measure the diameter and note whether the old part screwed inside the spout (male) or over it (female) so you buy the matching aerator.
- Pick a low-flow aerator — basin versions often rated around 4–6 litres a minute, versus a typical tap's 10 or more — and keep the old rubber washer if the new one doesn't include one.
- Screw the new aerator on hand-tight, then nip it up gently with a cloth-wrapped wrench so it doesn't drip.
- Run the tap and check for leaks round the thread; the stream should feel soft and full, not weak.
- Repeat on the kitchen and other basins — they each take the same couple of minutes.
Pro tips & pitfalls
- Take the old aerator to the shop or order a small assorted kit — there are several thread sizes and the wrong one simply won't seal. The kit saves a second trip.
- Unscrew and rinse the aerator every few months, especially in hard-water areas: trapped limescale and grit weaken the spray and make a good aerator feel broken.
What it's good for
Good for the planet
- Saves water A low-flow basin aerator can roughly halve the litres-per-minute at the tap — from around 10 down to 4–6 — for handwashing, shaving and brushing.
- Saves energy Every litre of warm water you don't draw is hot water you didn't have to heat, so your boiler or instant heater works less.
Good for you
- Saves money On a metered supply the part costs only a few euros and trims both the water bill and the heating cost behind every hot-tap use, often paying for itself within months.
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