Growing marijuana, same as other plants, presents distinct nutrient requierements in funtion of which part of the cycle we are. One of the worst nightmares for growers is to find what nutrients to use and what dosage. What is common is to control pH levels of the water used, but many growers forget to worry about Ec levels (water conductivity levels).
Electroconducivity shows us in a digital number how much salts are dissolved in that water. A high Ec can damage the plants as a low Ec can be not enough for plants expectation.
How to know water's Ec
First step in Ec control is a Ec digital tester. Those tools give you an accurate value of salts dissolved in water, helping grower's job.
Once we have on EC tester, we proceed to water reading. Those waters with an Ec level higher than 0.4 should not be used ( we don't know wich minerals are on it so it is better to not using). Waters with an Ec level less than 0.4 (400ppm) are good enough to use them. The use of watering filtering systems can increase a lot the yields of a garden making the invest a proffit deal.
How to add Calcium and Magnesium to water
Calcium and Magnesium are trace elements needed for a healthy growth. They are frecuently used to correct deficiences in some cases too. Most common way to found them is in a liquid form. Comming from a filtered water with an Ec level roundin 0.01, we should add Calcium until we reach 0.2 (200ppm) and then add the Magnesium until we reach an Ec of 0.4. Once both are added we can start adding nutrients to the mix until desired Ec level (depending on the week of growth we are, if they are flowering or not...)
Higher Ec recommended by Sant Yerbasi: Ec=1.6
Recommended Ec levels for vegetative phase
On its first phases, marijuana, has enough with an Ec= 0.6-0.8. When they are on an advanced vegetative phase (or mother plants) maybe it is better to reach an Ec=1-1.2
Recommended Ec for flowering phase
Ec values to manage marijuana can vary substantly, from one species to others and between growing systems. The higher Ec level are found in soil, but in coco, hydroponic and aeroponic systems, growers must use softer levels of Ec to not overfertilize the plants (in these systems with no substrate it is easy to overfertilize plants).
As a tip we could say that maximum Ec level should be rounding Ec=1.6 (some strains can assimilate higher doses, but usually less is more: Plants are likely to have a low diet more than a overdose diet.
How to increase Ec levels?
Following instructions said above, if we want to increase the Ec level we just need to add nutrients to the water mix.
How to decrease Ec levels?
If we want to decrease Ec levels of water we need more water with lower levels of salts. We can act in two ways:
- Add more water (with a Ec=0.00) to the mix increasing the total volume of water.
- Take some liters out of the mix to then add the same quantity of water (Ec=0.00) to get same volume with less Ec.
In both cases we are trying to decrease the quantity of salts dissolved in water with a lower Ec water.
*Best way of non suffering of a high Ec level is to use water filtering systems.
Recommended Ec levels indoors and outdoors
Vegetative Phase: Ec not higher than 0.8 indoors or outdoors
Begining to Holf Flowering Phase: Ec not superior to 1.2 indoors and 1.5 outdoors
Half to End Flowering Phase: Ec not superior to 1.6 indoors and 1.8 outdoors.