thanks carl, after i asked the question i read the instuctions like you do and it was in there
.
it also says don't use it on water above 90ppm for it could damage the meter, oh well.
have you change over yet carl?
Thanks Malc
been trying to get my head round this for a couple of days now and to top it all off my bird wants to leave me cos she thinks i should get a proper 9-5 job like her!! no telling some people.