Merryterry wrote:
fail to see why cheap hoses would be any worse at harbouring germs
than expensive ones. Fall apart, yes, harbour germs probably not.

You aint seen the Electron Scan Photographs I have seen!
Could you accept that cheap extruded EDPM (synthetic rubber), made down
to a price and not made to any standard, can have a rough inner
surface. Could you accept that dearer EDPM hose, made to quality
standards, can be made with a smooth inner surface and tested as such
and against harbouring biofilms by an independant laboratory?

Can you accept that all domestic water supplies in the UK have a
chlorine content high enough to kill all bugs in the water?

Legionnaires disease occurs where stagnant water exists.