I'm thinking of investing in an under sink water filter that you need a plumber to fit, one that removes nitrates etc. I've read that they make the water softer too. Has anybody got any recommendations. I think you have to replace it every 12 months and you get a partial refund. Any advice appreciated!

We have a Springflow system on our kitchen sink.

It's a special tap (the hot works as usual, but the cold turns both ways - forward for normal water and backwards for filtered water), plus the filter unit that sits under the sink. With ours, the filter is replaced every six months, at a cost of £22.

The water definitely tastes better and it is softer (we live in a hard water area). I'd definitely recommend it.

Im thinking of constructing an RO water filter in rural areas where there is no source of electricity. I know that reverse osmosis filters require pressure but Is there any cost effective way to to obtain the energy to pressurize water?

Basically your question becomes "How do I run a pump without electricity ?".

Well, take off the motor and replace it with a crank, a water wheel, a wind turbine, steam engine, stirling engine, or something animal powered.

What kind of results did you have, does it improve the taste of the water enough to make it worthwhile?

my friend has one.
it doesnt change the taste at all. and you can not even tell how pure it really doesnt make the water.

you should just invest in a water filter jug that way you can chill the jug in the fridge