Salt water cycle

We are told regularly that, due to global warming (or to climate change, depending on the writer's or editor's viewpoint), the ice caps are melting, pouring millions of litres of fresh water into the oceans, diluting the salt content and threatening sea life.

So perhaps we need to use de-salination for our water supply. Then we can throw the salt back and re-salinate the sea.

Or would it be naive to suggest that like energy/matter, water is impossible to destroy? In other words, does water go round a closed loop, running off into the rivers and hence into the sea either directly or via our sewage works or via evaporation and eventual rain, so that there is no net change in the salinity of the sea water over time by utilising de-salination?

On another point, is Chris Finn's suggestion of using grey water for toilet flushing (Letters, 3 July) not just another ill-thought-out reaction? The grey water will contain soap, which will make a nasty mess in the toilet cistern which will then have to be cleaned regularly, probably with the cleansers causing worse pollution.

Also, holding tanks cannot be easily incorporated into the ceiling void of a modern house: there is very little space there and making a false ceiling would obviously lower the ceiling height in an already low ceilinged room.

And at the government's currently-recommended housing density, modern homes simply do not have enough spare space anywhere - even in the garden - for storage tanks.

Brian Hammond

Hunter Willis, Staffs

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