pH has a great influence on the availability of the different nutrient elements. Therefore be sure the pH is always in the right range. The best availability range in the substrate is from 5.2- up to 6.2.

But CANNA recommends a different range for each type of substrate:

EC means electrical conductivity. EC is a number presenting the total of dissolved salts in the water. They include salts originating from the water and salts that the nutrients added.

To ensure good root development the feeding water must be between 68 – 77°F. When it's below 59°F the roots’ capacity to absorb decreases quickly, which results in a smaller harvest. If the feeding solution is mixed using cold water then the pH will rise when the water is heated. In this case, a high pH can be avoided by setting the pH a bit lower from the start.