Understanding of PH/EC/PPM readings please?

jwilk02

Well-Known Member
Hi Guys,

I have a basic understanding of what they do and why it is important but i am unsure how to understand the data, I was wondering if someone can point me in the right direction please? Never used the TDS & EC meters before but i see allot of people saying how important ppm is so i thought it is time to learn.

PH 6.0 - R/O 5.6
PPM 0671 - R/O - 0980
EC - 1342 - R/O 1960

Any advice would be great, thanks guys!
 

Billy the Mountain

Well-Known Member
Can someone please explain to me these readings and what they mean?
No idea what the R/O columns signify. Did you create the spreadsheet?

In general, stick to EC values for measuring nute concentrations. PPM is a derived measure and is simply EC x a constant (usually 0.5). PPM is misleading because it does not reflect the total elemental PPM in solution (unless you're measuring NaCl). There's no reason to use both.
 

jwilk02

Well-Known Member
Hey,

Yes, I whipped up a quick spreadsheet (any good?) and R/O is run off (sorry should of said).

So just measure EC and not PPM?

Cheers Billy!
 

Tracker

Well-Known Member
No idea what the R/O columns signify. Did you create the spreadsheet?

In general, stick to EC values for measuring nute concentrations. PPM is a derived measure and is simply EC x a constant (usually 0.5). PPM is misleading because it does not reflect the total elemental PPM in solution (unless you're measuring NaCl). There's no reason to use both.
@jwilk02. Like Billy said here, in the case of the meter you are using, the PPM is just the EC divided by 2. Not all meters use the same conversion factor. EC is the more fundamental number to use. When I'm in late veg/early flower, when plants are the hungriest, I shoot for about EC 2.0 to 2.4. You can push it a little higher, like up to 3.0, if everything else is dialed in perfectly....lights, temp, RH, pH, co2, etc.... But I never try to push mine hard like that.

pH affects the capacity of the nutrient solution to exchange ions with the plant. To get optimal exchange, the solution needs to be slightly acidic within a range. If the solution is outside of the optimum range, the nutrients are not optimally available for the plant to uptake.

Influence of pH level on nutrients.PNG
 

jwilk02

Well-Known Member
@jwilk02. Like Billy said here, in the case of the meter you are using, the PPM is just the EC divided by 2. Not all meters use the same conversion factor. EC is the more fundamental number to use. When I'm in late veg/early flower, when plants are the hungriest, I shoot for about EC 2.0 to 2.4. You can push it a little higher, like up to 3.0, if everything else is dialed in perfectly....lights, temp, RH, pH, co2, etc.... But I never try to push mine hard like that.

pH affects the capacity of the nutrient solution to exchange ions with the plant. To get optimal exchange, the solution needs to be slightly acidic within a range. If the solution is outside of the optimum range, the nutrients are not optimally available for the plant to uptake.

View attachment 5308330
Thank you so so much!! Really thank you!! I am so interested in the science behind growing it is so fascinating!!!
 

Tracker

Well-Known Member
Thank you so so much!! Really thank you!! I am so interested in the science behind growing it is so fascinating!!!
Some useful pics that you see around the forums.....
Asset-2@300x-100-1024x748.jpg
KRuFnY4-768x770.jpg
NutrientAntagonism-2-800x570.jpg

If you want textbooks for reference, search around for horticulture, agriculture, plant science textbooks. Google search for textbooks on those topics.....

Then, LibGen is a pretty good place to find pdf books.
 

coreywebster

Well-Known Member
Hey Kerowacked thanks for your reply, i am growing in canna coco pro plus i thought in coco should be between 5.8 and 6.2 or am i wrong?
Cheers mate,
It's not inert.

There's a fair amount of K in new coco for example.

So expect it to be higher EC coming out with new coco.

Worry about what you are putting in.
Ph 5.8-6.2
About 2/3rds of recommended EC from cannagrowguide.

Only check run off when you have an actual problem so you can eliminate salt build up.

Don't check run off ph


As long as you ph right and don't overfeed or constantly let it dry out fully you shouldn't have many problems and even then they won't usually present themselves in early flower
 

coreywebster

Well-Known Member
"As long as you ph right and don't overfeed or constantly let it dry out fully you shouldn't have many problems and even then they won't usually present themselves UNTIL early flower"
 
Top