QUESTION: I went from a flood and drain set-up to a cocoa and pearlite mix, but I’m still using GH hydro nutes. Is there a simpler set up? Also, can you explain the difference between pH and PPM?
Dru West: If you are a beginning grower, growing in soil or coco is the simplest way. Hydroponic systems like your old flood table can introduce a number of different variables that make learning more difficult. The fact that you have added perlite to your coco will cause you to have to water more often than if it was just straight coco. This is cool it just requires a bit more attention.
When using coco, PPM (parts per million) is important to monitor. This is because coco is an inert medium, meaning it contains no nutrients (unlike soil). You must monitor the levels to ensure proper plant growth. The PPM is the measure of the solid particles (nutrients) in the water. In order to accurately determine the amount you must first measure the PPM of the water you are using. This number must be subtracted from total PPM level after the nutrients are mixed in to determine how many parts per million contain usable food for the plants.
pH on the other hand is the measure of how acidic your soil/nutrient solution is. pH works on a scale of 1-14 (1-7= acidic 8-14 = alkaline 7= neutral). pH is important because the roots can only absorb the nutrients they need for growth, if it is correct. Ideal pH levels: Soil- 6.0-6.3 Coco/hydro- 5.8-6.0
So be sure to adjust your pH and PPM levels before every watering. There are many affordable digital meters that will check both of these things for you so be sure to get one.