John Rumm wrote in
o.uk:


http://www.screwfix.com/p/polyphosph...nhibitor/68371

Hi John,
Thanks for the tip. Do you have to buy a 'cartridge' for that model, when
it runs out? I had a vague idea that some phosphate dosers can be refilled
with generic phosphate balls (which would be useful if the cartridge-maker
goes bust).

A