We have just built a shower room on the third floor of a building we
own. The hot water is heated by a tank which does the entire building
and the cold water is direct mains.

We are using a monsoon 4bar pressure pump to increase the hot water
flow, which has its own supply from the tank on the ground floor.the
cold is mains fed

The shower works a treat but as we are in a hard water area the
build up of scale on the shower doors and wall is quite noticeable.

can some recommend a way of softening the water for the shower only,
the pipe work is plastic by the way

further question?

does the scale come from both the cold and hot water or is one worse
than the other for scale.

TIA