PH and EC levels


For soil cultivation, there is a common rule among growers, which is to use 50% of the dose recommended by the manufacturer. Growers follow this rule, without actually knowing the concentration of salt they are giving their plants. For soil cultivation, an EC meter is the most important tool for achieving the correct dosage. That is why all the people who value their plants cannot fail to make this small investment (around R $ 120.00)

To demonstrate how important it is to know EC, we tested 5 popular fertilizer brands. Only fertilizers for flowering were tested, because it is at this stage where the growers fertilize more frequently (following the idea that with more fertilizer, they will have greater production) and during this part of the life cycle, the plant becomes more sensitive to accumulation of salts.

Before looking at the results, it is important to understand one thing: Generally, no one should fertilize with EC above 0.8 when using soil (soil)

And that is why the first important step is to discover the EC of your tap water. In this simple example, we use a mixture of 50-50 piped water and reverse osmosis water to arrive at the

EC of 0.43. Obviously if you have a value above 0.8 in your tap water, you will have to lower your EC through filtration. For small gardens, a normal filter is sufficient if you don’t have the money to buy a reverse osmosis system. A conventional filter should reduce the EC between 0.15 and 0.20. Another alternative would be to buy gallons of mineral water to use only when fertilizing. A good mineral water has EC around 0.25.

Let’s start with the labels on the bottles. What most do not know is that the manufacturer’s recommendation assumes that water with EC 0.0 (water from reverse osmosis) will be used.


Ionic recommends an EX of 2.0 for the flowering phase in hydroponics. From this value, growers have to deduct the value of their tap water (tap) to be able to calculate the recommended dosage. Let’s assume that your tap water has an EC of 0.6. We calculated from the recommendation 2.0 – 0.6 = 1.4 EC. The maximum recommendation will then be 1.4 EC.

Canna and other Dutch companies generally recommend even higher values. So the need to know this formula becomes very necessary. Even if one wonders how the plants would survive for a long time with 2.0 and 2.2 EC, the vast majority of growers use high dosages in their grow, because they do not know this essential information. The result is not just an excessive expenditure of fertilizer on the hydroponic solution, but taking care of the plant becomes much more complicated and problematic. Flushing regularly is mandatory with such high EC levels. On the other hand, plants grow very fast (they stretch and stay with a lot of leaves, etc.), and they develop complex symptoms of little and a lot of fertilization due to the high accumulation of salt in the substrate. In the end, high doses of nutrients lead to a high risk of mold in the flowering stage, reduced resistance to pests, minimized production and can cause health risks by leaving radioactive traces in cannabis (through phosphate).


How are you measuring the pH of your water and land? Do you have an EC meter in hand?

It is expensive, I know … but it is worth the effort. Only with these two meters will you find out if you are feeding your plant correctly. PH regulator, I usually use products for aquarium (or pool). With lemon or vinegar, I had a very strong pH fluctuation and could not have a good control.

Fertilizers in general tend to drop the pH of the water absurdly, so if you don’t have a pH control (meter) … the nutrient solution will only bring problems (locking in nutrients and fluctuating the pH of the soil). A pH and EC meter is extremely necessary when fertilizing in soil.

Just for example:

My tap water (piped) has an EC of 1.22 … Which already completely exceeds the limit for safe fertilization.
Gallon mineral water that I bought, has EC of 0.63 … It already gives me a small margin to fertilize. (This will vary with each brand of mineral water)

Dilute twice the recommended water (50% of the dose), it can still be very toxic for your plants … everything will depend on your initial water. (filtered, reverse osmosis, mineral, piped)

Make an effort and get both meters (and calibration solution for both).

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