Jump to content
  • Sign Up

How to read my EC/TDS meter?

Recommended Posts

Hi guys,


just got my EC/TDS meter so i can check on things.. 


I already have a PH meter and PH in my Rez is at 5.9-6.1 in vege stage still




I got my EC Meter


What are reccomended levels for growing in hydroton clay balls?


and how do i read my meter


When people say " an EC of 1.8"  what mesurement do i take that from?  


my EC/TDS meter has these options:



- ppt   ?


- ppm   ?


- mS    ?


- uS (well its a backward u)   ?


which ones do i read and what are reccmended levels throughout vege and bloom stage?

Link to comment
Share on other sites

Oh the fun of ppm/ec/etc......


All measurements are taken as EC as that's the way the meters work. If you have a PPM meter it measures EC then using a formula inside it converts it and shows you the PPM. The EC (and therefore the PPM) also changes as temperature changes as well and a good meter (like one I CAN'T afford) will take the temp of the water and include it in calculations.


The best I have found in my recirculating system (just a little different from yours) is to keep it between 5.8 and 6.1 PH for veg and slightly more acidic for Flower (5.4 lowest) gives the best results for me.


Now as to ppm I kept mine at (about) 1400ppm. (reasons for me) weed likes about 1400 to 1800 ppm  but I found it would rise on its own during the week towards the end  between flushes so by starting at 1400 if for some reason I cant get to the tent for a day or two I know its not going over. Also allows for a little extra nute push in flower.




Consistency is the key.  If your meter reads 1200 PPM and you have all your nutes in AND your plants IN THIS GROW are happy then that's what you use THIS TIME and you will succeed.



I have attached a simple chart conversion for your EC to PPM to Australian PPM. Just enter the starting PPM of your water and the EC on bottle for value. (checked free of viruses)

EC PPM Calc.zip

  • Upvote 1
Link to comment
Share on other sites

Hey Qwobbler,

I use an older Truncheon but it has 3 measures EC, CF and PPM. I use PPM. I run at around 1200 to 1400 PPM. In EC that's equivalent to 1.8 to 2.0. In CF that's equivalent to 18-20. Some people vary their levels from grow to flower. I do not. Now these levels that I use are much lower than those recommended by the nute manufacturers but I find I have a much better rate of growth and less burning in lowering the recommended salts.



  • Upvote 1
Link to comment
Share on other sites

hmmm i only have 946 ppm....


so does that mean more nutes?


im a total beginner with this stuff, have gotten 4 weeks through vege now and havnt used any PH or EC meters and everthing looks healthy, just curious as to how to keep my EC and PH in good order :)


My bore water i use is 6.0-6.1Ph  and at 162ppm

Edited by qwobbler
Link to comment
Share on other sites

My starting is (wait for it) 576 and I run at about 1400 as I said so if we take the 300 odd diff between yours and mine and add it to your 946 +300 = 1246

so that's close to mine. check your plants after a couple days they will tell you if its TOO low or TOO high.


Maintance during grow for me is everyday top up rez with PH stable water up to the outlet pipe

check the PH and adjust (PH first cause PH down has a marked effect on PPM)

then check PPM  (should have dropped a little at beginning of week as the plants feed then lvl off mid week as salts and waste build up to match feeding then toward end of week (just before wekly flush) it will start to rise.)

Check water holes for blockages

pull dead or useless leaves


takes me about 15mins a day


Once a week I drain the rez and use it on the Veggie Garden, fill with PH balanced water and flush by running 2 feed 1 after the other.

Dump that water and refil

add PH adjust and nutes

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using the community in any way you agree to our Terms of Use and We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.