Nutrient Salts Meter

[Amanda]

i would like to know any information you might have on using a nutrient Salts Meter, i have bought one of these and have been told that they are vital for optimum results. i am told to keep the CF level on 8 but it seem to read almost 8 with no added solution. i have read the instructions carefully and cant see what i am doing wrong, my ph reading stays pretty accurate. Please send me any information u think i might need. thank you. Amanda vamskd00@iinet.net.au