HM Digital COM-100 EC/TDS Metre Help

Hello,

This is my first grow and I have a couple of weeks left of flowering. It is 2 plants in a RDWC setup.
Everything is fine now, but in the beginning I could never work out how to use the COM-100 Metre, so I haven't been using this the whole grow. I just mix to the directions on the back of the CANNA bottles, being 40ml per 10 Litres of water. Drain and refill reservoir once a week.

There is another post on this using the HANNA metre but it is so hard for me to understand. If anyone could help please.

The device has two main settings, each with three separate settings for that main setting.

ppm (KCI - 442 - NaCI)
uS (KCI - 442 - NaCI)

So there are 6 settings to chose from..

What setting do I put it on to measure PPM?
Is TDS just another name for PPM?
If so, what is EC for?

Thanks for your time.

Hey bud, I have the same TDS and I was confused as hell at first as well.
Instead of looking at the ppm I just look at the ec readings as ppm is just a conversion from ec and can differ depending on the conversion factor (KCI,442,NaCl)
Just cycle thru the modes til you get:
mS
0.00
Temp reading

Hope that helps!

SmokeNfish said:

Hey bud, I have the same TDS and I was confused as hell at first as well.
Instead of looking at the ppm I just look at the ec readings as ppm is just a conversion from ec and can differ depending on the conversion factor (KCI,442,NaCl)
Just cycle thru the modes til you get:
mS
0.00
Temp reading

Hope that helps!

Click to expand...

Hey thanks I understood that first bit.

When I am cycling through does it matter which uS setting it is on (KCI,442,NaCI).. Or did you mean just cycle through until I hit the first one, which would be uS KCI and not worry about 442 or NaCI?

Cheers

Its the setting after uS, cycle til you get mS, then there wont be any other settings.

SmokeNfish said:

Its the setting after uS, cycle til you get mS, then there wont be any other settings.

Click to expand...

Sorry I thought you originally misspelled uS as mS. Mine doesn't have mS. It cycles through ppm and uS settings and then back to ppm. There is no mS after uS.

Thanks anyway ill try work it out

Add: I just looked up the com-100 and the new model has mS and ppt added..
My com-100 is about 4 years old, never been used until now.