Hammerhead Works:
Advanced Nutrients Hammerhead is the modern alternative to standard PK-type flowering stimulators available today. PK boosters were originally designed a long time ago for outdoor agricultural use, where phosphorus is quickly depleted from the soil. With indoor cultivation, this does not happen, and therefore, the ideal P and K ratio is different. Advanced Nutrients has formulated Hammerhead to have the ideal P and K ratio for indoor gardening. Hammerhead provides exactly the right amounts of additional P and K for optimal flowering enhancement without over-fertilizing or burning plants. 
Keep in mind that Hammerhead is not part of the "pH Perfect" range of Advanced Nutrients products, and if Hammerhead is used, you will need to regularly check and adjust the pH of the tank.

How to Use Advanced Nutrients - Hammerhead:
Advanced Nutrients Hammerhead is suitable for use in any type of hydroponic cultivation system in the first 2 weeks of the flowering cycle. To use it, simply prepare the nutrient solution as usual, check and adjust the concentration as needed, then add Hammerhead at a rate of 2 ml/liter and mix well. Adjust the pH to the required value.
As with all nutrients, boosters, and additives, never mix them together in their concentrated form (i.e., directly from the bottle). Always add each nutrient, booster, or additive to the tank water or feeding water one at a time, mixing the solution well before adding the next one.