What is ppm And ec

could somebody please explain in very simple terms how I figure out what my ppm and EC should be for a flowering plant in soil

Parts per million is an value of total dissolved solids of the metallic type that exists in a liquid. It is measured by electric conductivity hence EC. A small electric current is passed through the fluid via 2 electrodes and the molecules that are conductive are detected. You will note that magnesium, calcium and phosphorus are all conductive elements while chlorine is not. This is why chlorine is not detected by an EC pen. When you mix nutrients in water it will be measured with an EC pen. If you use standard tap water and let the chlorine de gas overnight, you will find if you test with the pen it has PPM already because there are minerals already dissolved in the water. You have a target EC that can’t be exceeded in your fertilizer mix and that stuff in your water needs to be accounted for too. Does this all make sense?
So to summarize, let’s say you want to mix your solution to 350 PPM and your tap water has 100 PPM in it already you can only mix 250 ppm of fertilizer in to your solution. Thus that is your usable overhead. The downside is you will not know what is in your tap water without it tested by a 3rd party unless your water utility reports the breakdown. Generally if your water tests is 100 ppm or less you can use it. If it’s more, you may want to buy an RO machine.


suggest you access the Freed Grow download here…for good information.

Also…buy a PH n PPM Meter set onilne for $20…critical


For early flower I like to feed around a 1000 ppm late flower I like to feed around 1200 ppm. Watch the way your plant responds it will tell you if it needs more or less hope that helps good luck

What new guys don’t realize is that the 1000 ppm you are mixing is a flowering formulation not a veg formulation. The same ppm with a nitrogen mix will catch your plants in fire!


I agree I should have stated Bloom nutes low in nitrogen .