optimal PPM for vegetative etc..

Roseman

Roseman

Elite Rolling Society
PPM for Hanna Chart PPM


Seedlings, Early Sprouts 100 to 250

Early Vegging 300 to 400

Full Vegetation 450 to 700

Early Blooming 750 to 950

Full Mature Blooms 1000 to 1600

Note: EC Calculations are different, here's a conversion chart :
heres a great chart that shows how different PPM can be from meter to meter... EC is the only real universal language...


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bender420

bender420

Well-Known Member
I know what EC is and what PPM but I am not sure why the PPM readings are different from meter to meter. Could anyone please elaborate a bit. Thanks a bunch.
 
MostlyCrazy

MostlyCrazy

New Member
Different way they count the nutrient salt molecules and tempature variation adjustments. My TDS meter have 2 or 3 ways to figure PPM.
 
BizarroOH!

BizarroOH!

Well-Known Member
is it true that when using hydro or aeroponics that you need to keep PPM lower at higher elevations, at 5000 ft or more?
 
BizarroOH!

BizarroOH!

Well-Known Member
I read something about dissolved oxygen levels being lower at higher elevations, and I was wondering if that would effect the amount of nutrients you would use in a hydro system specifically aero : )
 
MostlyCrazy

MostlyCrazy

New Member
OK, just googled disolved oxygen and it says that the level is affected by the level in the surrounding air (at 5K I would suspect your oxygen content is lower than mine here about 200 feet above sea level), aireation and what the plant gives off. I would say yu definately want to compensate by running a lot of air stones in you res.

Here's what I use:

This pump:

http://www.discount-hydro.com/productdisp.php?pid=412&navid=8

With there airstones: I use the 4"

http://www.discount-hydro.com/productdisp.php?pid=548&navid=8

The pump comes with a 4 way spliter and I use 2-3 per 10 gallon res and the water just boils and spalshes which is what I want! Big air also soves or prevents lots of root problems.


I'd also see what I could do about getting the humidity up over 60% at least for veg and then lower it to under 45% during flower. It will help the plants breath.
 
J

jayww

Member
Roseman said:
PPM for Hanna Chart PPM


Seedlings, Early Sprouts 100 to 250

Early Vegging 300 to 400

Full Vegetation 450 to 700

Early Blooming 750 to 950

Full Mature Blooms 1000 to 1600

Note: EC Calculations are different, here's a conversion chart :
heres a great chart that shows how different PPM can be from meter to meter... EC is the only real universal language...


__________________


Roseman's DIY Bubbleponics-DWC Tutorial


Questions about Bubbleponic Growing Thread
Click to expand...

Any idea as to what a blue meter PH tester would be relative to this chart..
 
skokie

skokie

Member
My Hanna and my Bluelab are almost dead on one another for PH... That's all they test though.

Also, OP, most nute manufacturers have charts specific to their products. I use Fox Farm and they recommend different levels than the ones RM list. Though at the levels he posted, I would feel confident that FF would perform well and not burn the plants.
 
N

NoDrama

Well-Known Member
MostlyCrazy said:
So that means that the Blue Labs portable reads the same as the Hanna ppm list. Thanks for getting that settled!
Click to expand...

Not necessarily true, read all about it here....


mogie said:
Does this help?

Total Dissolved Solids (TDS) is the best measurement of the nutrient concentration of a hydroponic solution. To estimate TDS, one can use a meter that measures the Electric Conductivity (EC) of a solution, and convert the number to TDS in parts per million (ppm). Many meters will do this conversion.

Total dissolved solids (TDS) is typically expressed in parts per million (ppm). It is a measurement of mass and determined by weighing, called a gravimetric analysis. A solution of nutrients dissolved in water at a strength of 700 ppm means that there are 700 milligrams if dissolved solids present for every liter of water. To accurately calculate total dissolved solids (TDS), one would evaporate a measured filtered sample to dryness, and weigh the residue. This type of measurement requires accurate liquid measurement, glassware, a drying oven, and a milligram balance. Example: 50 mL of the 700ppm solution would leave 35 mg of salt at the bottom of a crucible after drying.

Electrical Conductivity (EC) is expressed in siemens per centimeter (s/cm) or milliseimens per centimeter(ms/cm). It can be determined with an inexpensive hand held meter. Nutrient ions have an electrical charge, a whole number, usually a positive or negative 1, 2, or 3. EC is a measurement of all those charges in the solution that conduct electricity. The greater the quantity of nutrient ions in a solution, the more electricity that will be conducted by that solution. A material has a conductance of one siemens if one ampere of electric current can pass through it per volt of electric potential. It is the reciprocal of the ohm, the standard unit of electrical resistance. A siemens is also called a mho (ohm backwards).

For convenience, EC measurements often are converted to TDS units (ppm) by the meter.

The meter cannot directly measure TDS as described above, and instead uses a linear conversion factor to calculate it. Everyone’s nutrient mix is different, so no factor will be exact. The meter uses an approximate conversion factor, because the exact composition of the mix is not known. Conversion factors range from .50 to .72, *depending on the meter manufacturer, which do a good job of approximating a TDS calculation from the meter’s measurement of EC.

* All ppm pens actually measure the value based on EC and then convert the EC value to display the ppm value, having different conversion factors between differing manufacturers is why we have this problem communicating nutrient measurments between one another.

EC is measured in millisiemens per centimeter (ms/cm) or microsiemens per centimeter (us/cm).

One millisiemen = 1000 microsiemens.

EC and CF (Conductivity Factor) are easily converted between each other.
1 ms/cm = 10 CF

"The communication problem"...
So again, the problem is that different ppm pen manufacturers use different conversion factors to calculate the ppm they display. All ppm (TDS, Total Dissolved Solids) pens actually measure in EC or CF and run a conversion program to display the reading in ppm's.

There are three conversion factors which various manufacturers use for displaying ppm's...

USA 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
European 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Australian 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

For example,

Hanna, Milwaukee 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
Eutech 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Truncheon 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

Calculating the conversion factor

If your meter allows you to switch between EC and TDS units, your conversion factor can be easily determined by dividing one by the other.

Place the probe in the solution and read TDS in ppm. Change to EC on the meter and read EC in ms/cm.

Conversion factor = ppm / ec.

[Note: ms must be converted to us: One millisiemen = 1000 microsiemens (1.0 ms/cm = 1000.0 us/cm)

According to the chart below:
1.0 ms/cm = 500 ppm (USA Hanna)
1000 us/cm = 500 ppm

Conversion factor = ppm / (ms/cm * 1000)
.50 = 500ppm / (1000us/cm) ]

The answer is your meter's convertion factor and should be a number between 0.50 and 0.72 To improve accuracy, take ec and ppm readings from your res daily for about ten days. Average the conversion factors. The more data points that you use, the closer you will be to finding your true conversion factor.

When reporting your PPM in a thread, please give the conversion factor your meter uses. For example: 550 PPM @0.7 or give the reading in EC, which should be the same meter to meter.

It may also be advisable to give the starting value of your water; there is a huge difference between RO and distilled water with a PPM of approximately 0 and hard tap water of PPM 300 @.5 (notice the conversion factor so others can work out the EC) or well water with a conductance of 2.1 ms/cm.


A note to Organic Growers:
An EC meter has fewer applications for a soil grower because many organic nutrients are not electrically charged or are inert. Things like Superthrive or Fish Emulsion, blood meal, rock phosphate or green sand cannot be measured with a meter reliably when they are applied or in runoff. Meters can only measure electrically charged salts in solution.
Click to expand...
 
captain insaneo

captain insaneo

Well-Known Member
So then if EC is the universal language is Roseman saying

Seedlings, Early Sprouts 0.2 to 0.4

Early Vegging 0.6 to 0.8

Full Vegetation 0.9 to 1.4

Early Blooming 1.5 to 1.9

Full Mature Blooms 2.0 to 3.2

Or am I missing the point
 
panta

panta

Well-Known Member
captain insaneo said:
So then if EC is the universal language is Roseman saying

Seedlings, Early Sprouts 0.2 to 0.4

Early Vegging 0.6 to 0.8

Full Vegetation 0.9 to 1.4

Early Blooming 1.5 to 1.9

Full Mature Blooms 2.0 to 3.2

Or am I missing the point
Click to expand...
thats exactly what i wanted to ask,what would be a EC feeding chart like the one roseman said in ppms,isnt that a little too strong
 
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