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I'm looking at that limescale filter pictured: and I don't think it helps with hard water at all.

It looks like the point of the limescale filter in the picture is for keeping the limescale IN the kettle, and preventing chunks of limescale from pouring out of the kettle and into your teacups. Anything else, it'd be utterly useless for.

A tiny metal mesh won't do anything to pull limescale out of hard water. For that, you need Reverse Osmosis and/or demineralizer. Much larger activated carbon-filters (aka: Brita) barely helps with hard water in my experience (and Youtube tests suggest it doesn't change ppm counts much at all).

(Brita clearly makes a different taste: so its filtering something out of the water. But its just not limestone / scale / the stuff that makes hard water)

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Descaling with vinegar (or citric acid tablets, or some other acid) seems to be the easiest solution, short of a more expensive, dedicated filter (like Reverse Osmosis).

You're just not going to soften hard water with a reusable mesh. That's just not how hard water works.

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IMO: That's why we don't see limescale filters on electric kettles. Physics / chemistry simply doesn't work the way the parent post expects.




> It looks like the point of the limescale filter in the picture is for keeping the limescale IN the kettle, and preventing chunks of limescale from pouring out of the kettle and into your teacups.

That's the point, yes. You have tea with lime flakes otherwise.

As for filters I actually prefer the taste of hard water (and the tap water is good to drink where I live, just inconvenient).

As for kettles - most people where I live use the ones you put on your gas stove as electricity is more expansive.


It takes around 1/5th kWh to boil a liter of water, or around $0.04 for me (in a place of fairly expensive electricity for the US).

How much cheaper would gas have to be for me to choose gas over electric? Probably $0.25/liter or more cheaper.


People I know with gas or induction stoves use it to boil water because it's faster. This must be doubly true in the US with it's comparatively weak power outlets.


I measured. It takes fully twice as long on a gas range burner, with a wide, flat-bottom kettle.


I have no reason to doubt your result for one specific electrical kettle and one specific gas stove.


It looks like the point of the limescale filter in the picture is for keeping the limescale IN the kettle, and preventing chunks of limescale from pouring out of the kettle and into your teacups. Anything else, it'd be utterly useless for.

Well, yeah. That's exactly what it's for. The kettle I'm using right now has one and that's exactly what it's for.


Just trying to understand your thought process here - did you think that the parent thought that the filter would somehow remove lime out of thin air? I'm honestly amazed how you didn't immediately come to the conclusion that it's just for filtering lime out before pouring.


I have been in homes with hard water, but its not my day-to-day life.

I usually use a $15 kettle, and no lime precipitates when I typically use a boiler. I can see that lime eventually builds up in the kettle, but as described earlier: a bit of vinegar removes those deposits without much issue.

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Honestly, I can't say that I've ever seen water so hard that it'd precipitate visible amounts of lime in a kettle. I usually see that sort of stuff on humidifiers or distillers. Not really a kettle.

I mean, everything eventually has lime buildup ("soft water" isn't free of lime/calcium, it just has 1/2 the calcium of hard water). Knowing how to clean that stuff off is important.


I had no idea how bad hard water could get until I moved to London.

I get limescale on everything. I descale my kettle every week or two (almost daily if not using a Brita filter), shower head monthly. I pour citric acid down the toilet weekly. My taps actually form little calcium stalactites over a few months. Thermostatic shower cartridges are an annual replacement item because the limescale gets them too.

I keep demineralised water around for sensitive equipment like humidifiers.

On the bright side, I love how hard water tastes.


I use the Brita Maxtra+, and have confirmed with test strips and en electric meter that it reduces my 400ppm to 150ppm or so. Not zero, but significantly increases the interval between rescaling and results in a more pleasant cup of tea. Not sure about the others, but the Maxtra+ is advertised specifically to soften water.

However the filters do not last as long as they claim. I have to replace the filter maybe 2/3 through it’s rated life or I start to get limescale and tea scum.

I don’t drink the Brita water though. I much prefer the taste of hard water.


I get that it's fun to try to "big time" me with physical explanations for simple phenomenons that anyone who actually owns a kettle can explain, but it's very simple: the filter isn't there to provide any kind of softening. It's there to keep chunks of limescale from falling out of the kettle when you pour the water.

Yep, that's the big mystery you couldn't solve in 30 sentences. It's a strainer.




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