Since beginning our testing of Rhiza Nova on cannabis, we have discovered some differences between how it reacts versus how our traditional agricultural crops reacted in earlier tests. The other crops (tomatoes, lettuce, alfalfa, etc.) could only tolerate 25% of normal nutrients, so I began testing with this amount. The cannabis responded with slow growth. After the first week of slow growth, I upped the dose of nutrients to 75% of normal, and when that was tolerated well, I gave them the full strength dose at the beginning of week 3. They have been absolutely thriving!
Also nice is the water savings. Using Rhiza Nova instead of running a sterile system has meant that I now have the ability to simply top off the water. The Rhiza Nova acts as a natural barrier for harmful bacteria. All I have to do is add a quarter teaspoon of molasses once a week to feed them, and they keep everything else at bay. No need to change the water weekly to keep the reservoir safe!
Another adjustment I decided to make was to increase the CO2 enrichment and temperature. The CO2 enrichment was boosted from 900ppm to 1300ppm. This was done so that the plants could tolerate a higher temperature. Cannabis plants do not like temperatures above 85°F (29°C) because their metabolism starts to run faster than they can breathe. Think of it like being winded from jogging. If they are exposed to high temperatures for long periods, they need extra CO2, which is what plants breathe, just as people breathe oxygen. Once they can catch their breath, they can grow faster and stronger without stress.
I boosted the temperature because the light was producing extra heat, which I had been fighting by exhausting the grow space frequently. The sensors were cooling the cabinet every time it hit 85°F(29°C) during the “day.” This was causing the fans to run nearly constantly. Now, fans running all the time is not a bad thing, but since a grower friend had such success with his own minor adjustments, I decided to follow suit. Now, my garden will be at 92°F(33°C), and thanks to the extra CO2, each one will be able to grow at a full sprint without losing their breath.
Note: My experience is that CO2 loses its effectiveness in the last 4 weeks of the flowering stage. I typically cut it out at this point. Some growers swear there are minute differences simply by using CO2 all the way through, while others feel that it is a waste of money after you are done with vegetative growth. Do your own research and experiment.
First time grower tip: Less is more. Start out simple, and make changes slowly. Remember that this plant grows on its own in the wild, and it only needs small bits of help from you to go from okay to great.