From seed…April 2nd…My plants are about 14 weeks old…when do you increase the phosphorus?
During early bloom (pre-flowering), cannabis will require additional nutrients due to excessive growth. Increase calcium and magnesium levels and dial in about 200–250 ppm of N-P-K (nitrogen, phosphorus, potassium). At this point, the grower should start feeding more potassium than nitrogen in preparation for the upcoming flowering stage.
During bloom, when vegetative growth comes to a halt, cannabis will require increased levels of phosphorus and potassium while needing only little nitrogen. When using commercial cannabis nutrients, flowering nutrients are formulated to accommodate these requirements. At about week 5 into flower (late bloom), shoot for about 125 ppm of nitrogen and provide adequate phosphorus once calyxes form.
That is very informative! Thank you!