Ppm info for soil

[email protected]

Well-Known Member
Anyone know a lot about ppm?

Please post your knowledge.

What is to high, what is a good number, at what number you should get an ro filter, basically an info you know would help.

thanks in advance ive searched and searched this forum for ppm info an found nothin.
:clap::clap::clap::clap:
 

ninjagaiden

Well-Known Member
soil you dont have to pay TOO much attn to PPM. if your plants are alive off the water you are feeding them now, you are fine.
 

Auzzie07

Well-Known Member
PPM stands for Parts Per Million. It is a measurement of TDS, or Total Dissolved Solids, within your water (be it minerals and chlorides from the tap, or the nutrients you dissolve within your water). You want to gradually acclimate your plants to higher and higher PPM's. As far as what is too high, or too low, that depends on how far along your plant is. Anywhere under about ~225 PPM (from the tap) is an alright starting base for water. The higher that number is when measuring tap water, the more contaminants you have in it (be is good minerals for you plant like Zinc, or bad stuff for your plant like Chlorine). For me personally, my tap comes out at around 185-200, and after letting it sit out for 48 hours, the chlorides evaporate and I'm left with water around 160-175 PPM. Some people say they don't go above 1000 PPM on their grows, and I've seen other people who don't go above 1900 PPM on their plants. It's all genetic-specific, some plants soak up nutrients like a sponge, where others prefer light nutrient feedings (slower acclimation to higher TDS). Hope this helps.
 

seanwinsall

Member
PPM stands for Parts Per Million. It is a measurement of TDS, or Total Dissolved Solids, within your water (be it minerals and chlorides from the tap, or the nutrients you dissolve within your water). You want to gradually acclimate your plants to higher and higher PPM's. As far as what is too high, or too low, that depends on how far along your plant is. Anywhere under about ~225 PPM (from the tap) is an alright starting base for water. The higher that number is when measuring tap water, the more contaminants you have in it (be is good minerals for you plant like Zinc, or bad stuff for your plant like Chlorine). For me personally, my tap comes out at around 185-200, and after letting it sit out for 48 hours, the chlorides evaporate and I'm left with water around 160-175 PPM. Some people say they don't go above 1000 PPM on their grows, and I've seen other people who don't go above 1900 PPM on their plants. It's all genetic-specific, some plants soak up nutrients like a sponge, where others prefer light nutrient feedings (slower acclimation to higher TDS). Hope this helps.
Good information to know. Now if someone isn't watching their ppm how drastically could it affect their yeild? Is it as important as ph?
 

Auzzie07

Well-Known Member
Good information to know. Now if someone isn't watching their ppm how drastically could it affect their yeild? Is it as important as ph?
Very strain dependent. Like I said, some strains can withstand a shitton of nutrients, some can be burned by the slightest bit too much. Is it as important as pH? Again, strain dependent. I have yet to touch my pH, or even test it in my grow, and all is going fine so far.
 

pointswest

Active Member
Copied this from GC poster joe-Fresh, explains how to convert water soluble ferts to ppm.

In the following example, Peters 20-20-20 is 728.3 ppm NPK. Add this to your water pps and you have the total pps. With most water soluble ferts if you follow the instructions for your particular brand you will be in a good range of tds for optimum growth with either the veg formulas or the bloom formulas.




One can estimate the parts per million in solution (ppm) produced by a quantity of fertilizer in a gallon of water, based on the fertilizer's N-P-K rating.

For each number in the rating apply the following formula:

> one teaspoon (5ml) of a given fertilizer in a gallon of water
(10xN)÷ 0.768 = ppm

> one tablespoon (15ml) of fertilizer in a gallon of water:

(10xN)÷ 0.256 = ppm


Example: Peter's Professional All-Purpose Fertilizer with N-P-K rating of 20-20-20.

(10x20)÷.768=260.4 ppm

Therefore, one teaspoon (5ml) of Peter's Professional All-Purpose 20-20-20 in one gallon of water will produce a solution that contains approximately 260.4 ppm of Nitrogen, 260.4 ppm of P (P2O5), and 260.4 ppm of K (K2O) for a TOTAL ppm of approximately 781.3 .


Explanation

It's important to understand that with the term "parts per million," we are expressing a measurement in terms of a RATIO, which, like miles per hour or pounds per square inch, is a relation in degree or number between two separate measurements. "Parts per million" is a common way of expressing the measurement of the dilution of something in solution, which for our purposes here, is the dilution of fertilizer components in water. It just so happens that fertilizer N-P-K ratings are also ratios, as is the measurement of teaspoons per gallon.

Parts per million is most often alternately expressed as milligrams per liter because it's so easy to convert due to the efficiency of the metric system: 1000 milligrams = 1 gram and 1000 grams of water = 1 liter; 1 thousand x 1 thousand = 1 million; voilá- parts per million.

Fortunately, the "parts" in "parts per million" are generic. It can be parts of a teaspoon just as easily as it can be parts of a gram. N-P-K ratios are also generic expressions of percentage, or parts per hundred. Unfortunately, 1 gallon does not equal 1 thousand teaspoons; it takes 768 teaspoons (or 256 tablespoons) to equal one gallon. But by knowing this, one ratio can be converted into the terms of another ratio, which is what the formulas above do.

Remember,

Before relying on these formulas to fertilize your grow, you should be absolutely aware that N-P-K ratings don't necessarily precisely describe the amount of each nutrient in the fertilizer, but instead describe the minimum amount of nutrient to be found, as explained in Mr.Ito's excellent FAQ on the subject.

The only way to know for certain the ppm of your fert mix solution is to measure it's EC, with an electronic TDS meter as you mix it. If this isn't possible, at the very least try to use only high-quality fertilizer brands with reputations for their accuracy and consistency of their analyses and products.
 
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