Citric Down will lower the pH level of your nutrient solution. The ideal pH for most hydroponic nutrient solutions is between 5.8 and 6.2, with some exceptions. Nutrient lockout will occur if pH levels are outside the optimal range. Citric acid is a weak acid and while typically it will drop pH levels, its instability will cause the pH to raise back up over a couple of days. To counteract this instability, Citric Down contains stabilizers which help to keep the pH at the optimum range. Future Harvest products are available for fall booking. Inventory is restocked once yearly, with potential for repeats based on order minimums.