The Grass Doctor

Is there any difference between making small ppm solutions from solid and liquid mother chemicals?

For example pesticides are generally liquid and fertilizers like uria, supherphosphet etc are solid. How do we calculate ppm from these things?

Public Comments

1. ppm is parts per million. There is no difference between solids and liquids if they are weighed. 1 ppm = 1 mgm dissolved in one litre of water. Most of the liquid fertilizers are near water in density (Slightly denser). In these cases 1 ppm = 1 microlitre dissolved in 1 litre water. As a rule of (green) thumb, 1 drop of liquid chemical in 1 litre water will be about 50 ppm.
2. The calculation is the same for the liquid and solids in figuring ppm. The problem that you are going to have to take into consideration is the solubility of the solids that you use. Figuring ppm of a solid that is only 50% soluble will throw your calculations way off.
3. Yes, generally a liquid mother chemical like Sulfuric acid or ammonium hydroxide is prepared into a ppm solution by taking a known volume of the mother liquid at a known specific gravity and concentration and obtaining the desired ppm end solution by serial dilution. With a solid a known amount is weighed out on a scale and added to a known amount of an acceptable solvent , dissolved, and then the desired straight solution is obtained by serial dilution