These days, many
in-ground swimming pools use a salt-water chlorinator to keep the water clean
and safe from nasty microbes.
The Pool Salt Meter at our local pool shop. Obviously, it does more than check dissolved salt levels - it also checks total dissolved solids. But it also costs more than $300 and, according to our friendly pool shop owner, " . . . costs a fortune to repair, too." We wonder why!
The chlorinator electrolyses the salt content of the water to
produce sodium hypochlorite which then acts like normal "pool chlorine" to
sanitise the water. Not having large amounts of chlorine in the water makes it
much more pleasant and you don’t come out of the water smelling of chlorine. Nor
will your eyes sting or your swimming togs become bleached.
However, for a salt-water chlorinator, there must be a minimum
concentration of salt in the water for it to work correctly.
Just how much is needed depends on the brand and model of
chlorinator but typically it is around 3000 to 4000 ppm (parts per million). If
the salt concentration goes below the specified level, you must add some salt to
On the other hand, you should not add too much as that is
simply wasteful and it might lead to accelerated corrosion of some of the pool
So how do you measure salt water concentration? Most people
don’t even bother. They just take a sample of their pool water to the pool shop
and ask them to test it (at the same time getting several other important pool
chemistry factors checked). If it is below the specified level, this is the
perfect opportunity for the pool shop to sell some bags of salt.