Reduce the pH level during the grow phase. Dutch pro pH down is manufactured from Nitric acid, so is perfect for plants in vegetative phases. For plants in bloom, it is recommended to use pH down bloom, which is formulated from phosphoric acid.
 
HOW TO USE
 
pH can fluctuate throughout the cycle of the plants.
 
If the pH goes outside of the range of between 5.5 - 6.5, the plants may stop up taking all the micro and macro nutrients, leading to signs of a deficiency even though there is enough nutrients in solution.
 
The pH needs to be monitored in order for the plants to continue up taking all the micro and macro nutrients.
 
Mix a small amount of pH adjuster at a time.
 
The best way to do this is to first dilute a small amount (1ml or so) of pH down into a separate container with about a litre of water and then slowly add this water, checking the pH of the reservoir after every small portion gets added, stop adding to the solution when the desired pH is reached.