ADVANCED HYDROPONICS - PH- DOWN GROW - 5LPH+ and PH are concentrated agents to reduce, or to increase, the acidity of the nutrient solution. With the right degree of PH the plants are able to absorb the maximum amount of nutrients contained in the watering. For PH adjusters during the growth period, use the PH+ Grow adjuster during the bloom period the PH+ Bloom adjuster Add until the desired PH is reached