Nice one.
Is it, that the windowcleaner who asks advice from members of this forum, whom you give advice to, time and time again regarding tds readings choose to ignore the 005, 006 or whatever readings they are, say that, the readngs are 035-036-046 whatever the reading is, and they are getting away with it).......................................
Maybe the customer is ignoring the fact that their windows may have the odd few spots on, but I am tired of tellling the man who does the windows, so I shall put up with it, cos Health & Safety Guidelines are saying, thats the way it is!
A SMALL RANT.
Change your filters like 'purefreedom of whoever you buy off, tell you to, or you will lose your're custards eventually.
Take the advice, or sod off and go to another forum.