Speaker 1: Welcome to brain Stuff from how stuff works dot com
Speaker 1: where smart Happens. Hi, I'm Marshall Brain with today's question,
Speaker 1: how does a water softener work? We call water hard
Speaker 1: if it contains a lot of calcium or magnesium dissolved
Speaker 1: in it. Hard water causes two problems. First, it can
Speaker 1: cause scale to form inside of pipes and water heaters
Speaker 1: and tea kettles. The calcium magnesium participate out of the
Speaker 1: water and stick to things. Eventually pipes can become completely clogged. Second,
Speaker 1: the calcium and magnesium react with soap to form a
Speaker 1: sticky scum and also reduces the soaps ability to lather.
Speaker 1: Since most of us like to wash with soap, hard
Speaker 1: water makes a bath or a shower less productive. The
Speaker 1: solution to hard water is either to filter the water
Speaker 1: by distillation or reverse osmosis to remove the calcium and
Speaker 1: magnesium altogether, or to use a water softener. Filtration would
Speaker 1: be expensive to use or all the water in a house,
Speaker 1: so a water softener is usually the less expensive solution.
Speaker 1: The idea behind a water softener is simple. The calcium
Speaker 1: and magnesium ions in the water are replaced with sodium ions.
Speaker 1: Since sodium does not precipitate out in pipes or react
Speaker 1: badly with soap. Both the problems of hard water are
Speaker 1: completely eliminated. To do the ion replacement, the water in
Speaker 1: the house runs through a bed of small plastic beads
Speaker 1: or through a chemical matrix called zeolite. The beads or
Speaker 1: zeolite are covered with sodium ions. As the water flows
Speaker 1: past the sodium ions, they swap places with the calcium
Speaker 1: and magnesium ions. Eventually the beads or zeolite contain nothing
Speaker 1: but calcium and magnesium and no sodium, and at this
Speaker 1: point they stop softening the water. It's then time to
Speaker 1: regenerate the beads or zeolite. Regeneration involves soaking the beads
Speaker 1: or zeolite in a stream of sodium ions. Salt is
Speaker 1: sodium chloride, so the water softener mixes up a very
Speaker 1: strong Brian solution and flushes it through the zolder beads.
Speaker 1: This is why you load up a water soften or
Speaker 1: with salt crystals. The strong Brian displaces all the calcium
Speaker 1: and magnesium that is built up on the beads and
Speaker 1: replaces it again with sodium. The remaining Brian plus all
Speaker 1: the calcium and magnesium is flushed out through a drain pipe.
Speaker 1: Regeneration can create a lot of salty water, something like
Speaker 1: twenty five gallons for each cycle. Do you have any
Speaker 1: ideas or suggestions for this podcast? If so, please send
Speaker 1: me an email at podcast at how stuff works dot com.
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