Marijuana growers often face a grow room problem called nutrients lockout.
It’s when individual nutrients elements–most often sulfur, magnesium, zinc, iron, phosphorus, or potassium–are present in the root zone but your plants can’t absorb them.
Nutrients lockout can happen when your cannabis root zone has the wrong pH.
It can happen when the marijuana root zone is overfilled with nutrients.
It can happen when you use polluted water rather than reverse osmosis water.
It can happen when you use crappy hydroponics nutrients such as Scotts Miracle-Gro, Botanicare, Emerald Harvest, General Hydroponics, etc.
Or all of the above.
Nutrients lockout is most likely to happen if you’re growing in soil, coco coir, soilless mix, or rockwool.
It’s not a common problem in pure hydroponics systems such as deep water culture and aeroponics.
Nutrients lockout is hard to diagnose. It can look like nutrients deficiency, overwatering, pests, or disease.
One immediate tactic for dealing with nutrients lockout is flushing your root zone with pure reverse osmosis water for one watering cycle.
Add Flawless Finish (a professional flushing product) to the water and adjust pH to 6.0.
Flushing overwaters your root zone, which can harm roots. So on the day you flush, dial down your grow room humidity to 49% for one lights-on and one lights-off cycle.
Do a foliar spray of 180 ppm at 5.7 pH containing B-52 and Rhino Skin the day after you flush your root zone.
Be sure the root zone is dried out before you water again.
When you water again the first time after flushing, use the following combination: beneficial microbes and a carbohydrate feed for them such as Voodoo Juice, Tarantula, Piranha, and Microbial Munch, and a half-strength dose of B-52.
After this, carefully use a hydroponics base nutrient in reduced dosage.
If your in bloom phase, use the base nutrients and bloom boosters at reduced dosages.
Increase dosage as you monitor for nutrients lockout.
Never exceed manufacturer’s recommended nutrients dosage.
In almost all cases, the manufacturer’s recommended dosage is too high.
Read the four-part series mentioned earlier to know what and how to feed after flushing so you don’t create nutrients lockout again.
At the very least, if the flushing does or doesn’t fix your problems, you’ll know if you even had nutrients lockout.