i grow in dwc and have done comparisons with and without gh powder and liquid koolbloom the liquid is a waste of money, however in my compasre the powder koolbloom actually increased yield and finished 2 days earlier than without.. also i do agree that having a healthy plant and leaves is key to good yields, bad nutes can cause burn, and other problems leading to a decrease in yields and potency...so yes having a healthy plant is most important,but if ur plants are healthy w/ whatever nutes ur using, a boost in phosphate levels during the last 2 weeks in bloom can increase bud size, density, and even help to finish sooner.. ive been doing compares for many years with many diferent nutes and aditives most are bullshit, but i can say koolbloom powder is the only one that actualy worked for me...