pH

Marijuana Horticulture

by Jorge Cervantes

The pH of a nutrient solution controls the availability of ions that cannabis needs to assimilate. Marijuana grows well hydroponically within a pH range of 5.5 – 6.5, with 5.8 – 6.0 being ideal. The pH in hydroponic gardens requires a somewhat vigilant eye. In hydroponics, the nutrients are in solution and more readily available than when in soil. The pH of the solution can fluctuate a half point and not cause any problems.

Roots take in nutrients at different rates, which causes the ratios of nutrients in solution to change the pH. When pH is above 7 or below 5.5, some nutrients are not absorbed as fast as possible. Check the pH every day or two to make sure it is at or near the perfect level.

Deviations in pH levels often affect element solubility. Values change slightly with different plants and grow mediums. Follow manufacturer’s guidelines for pH eve, and correct the pH using the manufacturer’s suggested chemicals, because they will react best with their fertilizer.

The pH can easily fluctuate up and down one full point in hydroponic systems and cause little or no problem with nutrient uptake.

Follow the directions on the container, and remember to mix adjusters into the reservoir slowly and completely. Fertilizers are normally acidic and lower the pH of the nutrient solution. But nutrient solution is still taken by plants, and water transpires and evaporates into the air, which causes the pH to climb. Stabilize pH f the water before adding fertilizer. Make a correction if readings vary on half point.