[L.Doubtfire - The Blade Runner]

Can anyone explain what is the difference between totally dissolved solids ( tds)
And parts per million ( ppm) is ? Thanks for replies.

Lewis  Doubtfire

[Moderator David@stives]

ie  there is 47 particles of desolved  solids in one million particles of water

[Ian_Giles]

Well I'm pretty sure that TDS just stands for total dissolved solids, ppm is of course parts per million, all just as you've said Lewis.
Put them together and the reading on the meter gives you how many totally dissolved solids there as parts per million.
I guess the ppm is the saturation or dilution level (depending how you look at it )

But I like Dave's way of putting it better than mine
Ian

[geefree]

Hi ,

With all the rain we have had, i left a large plastic container outside by accident, it was full of rain water so i popped the TDS meter into it, it read 0013 , yet our drinking water is 0136, and we use a ro unit to make it pure TO CLEAN WINDOWS!  ,

My son was a little confused he asked  " so the rain water is cleaner than the water we drink "

I aint that clever lol, and it was hard to expain.

Gary

[dai]

so the rain water is cleaner than the water we drink "

Not always the case, just has less minerals deposits in it.
Not all contaminates have solid particles.
You could half fill a glass with 0 tds water, and top it up with pure alcohol. It would still read 0 ppm. Dai