What EC levels are safe during flowering?

doser

Well-Known Member
My nutrient meter already has all the conversions on it lol just confusing when you don't know what PPM scale people are referring to.. When they are saying for example "i started off at 200 ppm and ended up at 1000 ppm" I find that really confusing... are they referring to EC x 500 or EC x 700????
Yeah that's what I'm talkin about. That and untill you run a grow and have plants burning at 1.2 you can't really know that the guy running 1.8 is running a pretty stiff solution. You need some kind of reference to base your opinion. Anyhow just my thoughts.
 

doser

Well-Known Member
I think if you want a solid number then go with the ? 1.0 or 1.2 1.4 etc scale
I think thats the same on everyones meter No?
 

jimmyjam22

Active Member
Yeah that's what I'm talkin about. That and untill you run a grow and have plants burning at 1.2 you can't really know that the guy running 1.8 is running a pretty stiff solution. You need some kind of reference to base your opinion. Anyhow just my thoughts.
What do you mean by "stiff solution"?
 

jimmyjam22

Active Member
I think if you want a solid number then go with the ? 1.0 or 1.2 1.4 etc scale
I think thats the same on everyones meter No?
Pretty sure all nutrient meter's have EC, CF, and at least one of the PPM scales depending on what country you live in...
 

BigBuddahCheese

New Member
I used to run my buckets at 1.8ec but I found that it was a bit too hot for my plants and now its down to 1.4-1.6 max seems to be a sweet spot for me.

What does the ec contain? What strain? A lot of factors determine how high of EC you can run. I mean I can put .3ec of nutes in and put 50ml of sweet in and have it jump to 1.2ec.
 

Dr marry jane

New Member
Different strains can handle more nuts that others. My blue dream it can handle an ec of up 2.9 = 2000ppm do some research on ya strain or strains ya growing c whats has worked for other people .
 

SableZen

Well-Known Member
It very well could be bullshit! I have yet to find a better answer tho!
Here's some of the full deal:

All EC/ppm/TDS/CF meters start by measuring the electrical conductivity (EC) of the solution. [This EC value is measured in terms of millisiemen (mS) or microsiemen (µS) per centimeter... 1000 microsiemen equals 1 millisiemen/centimeter.]

Because of this, an EC reading is basically universal (anyone can share an EC value and it will mean the same thing to everyone else). CF is simply EC x 10 [So a 1.0 millisiemen/cm EC equals a CF of 10] and is also universal, just not as commonly used and rather redundant].


Where it gets confusing:

After making an EC reading, TDS/ppm meters will automatically apply a conversion factor to guess at what the parts per million (ppm) is of anything that is dissolved in the solution being measured. Different uses/industries/locations use different conversion factors to guess at the ppm reading. For example, in the United States a .5 conversion factor is most commonly used: an EC reading of 1.0 millisiemen/cm will give you a 500ppm result [Hanna & Milwaukee meters are usually using a .5 conversion factor]. In Europe, a .64 conversion factor is most commonly used: an EC reading of 1.0 millisiemen/cm will give you a 640ppm result [Eutech meters are usually using a .64 conversion factor]. In Australia, a .7 conversion factor is most commonly used: an EC reading of 1 millisiemen/cm will give you a 700ppm result [Truncheon meters usually have both .5 or .7 conversion factors available for use in settings].

Because of this, and the failure of most people to state the conversion factor used when sharing their ppm readings, it's not really a universally accurate way to discuss nutrient solution strength.


The reason for different conversion factors:

Since the only true way of measuring total dissolved solids is impractical (evaporating all the water and weighing what remains), some baseline readings based upon the electrical conductivity of known solutions (and known TDS) were made:

TDS - NaCl: 0.47 to 0.50
TDS - 442: 0.65 to 0.85
TDS - KCl: 0.50 to 0.57

But since in hydroponics, we aren't growing in NaCl/442/KCl solutions... the true ppm is nothing but a close guess. But those measured solutions above are the reason for the range of conversion factors that exist as "close enough" for our purposes.
 
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