They won't see us waving from such great heights

[venta]

A question for those of a scientific turn of mind.

I live in Oxford which, as many of you know, is a hard water area. Our kettle needs regular de-scaling, as it quickly fills up with concrete-y white deposits. I'm sure the iron would too, if we ever used it.

Recently, the shower has been communicating to me that it needs de-scaling; it does this by running extremely hot. This isn't as daft as it sounds: scale lowers the water throughput, and thus the shower is heating much less water than it thinks it is, the net result being that it heats it too much (at least, that's my understanding).

It's always a fight to dismantle the showerhead, but when one does the deposits found therein always turn out to be a virulent shade of jade-green. Why ? Is it in fact not scale, but some mysterious by-product of a disintegrating copper water tank ?

And for those who are not of a scientific turn of mind: what do they call cider in America ?

Comments

[edling.livejournal.com]

""As the temperature of water increases, the volume of scale it holds in solution drops"
Thought that was a bit weird- it's a long time since I've done any chemistry but I remember vaguely that the solubility of anything in anything increases with temperature (summat to do with thermodynamics and entropy I think), and this sounds like it's going the wrong way.
Just had to go look it up and apparently it's more complex than the simple solubility I was expecting- at lower temperatures most of the scale is nicely soluble calcium bicarbonate, but above ~70C it starts decomposing to calcium carbonate (& carbon dioxide & water), and that's a lot less soluble so precipitates out.
Water chemistry always was too complex for its own good...

[venta.livejournal.com]

Well spotted - I read that line about the volume of scalde dropping as temperature increases without even realising it was upside-down.