there;s no secret bullet as much as the marketing follks want to sell us stuff.
If the plant is healthy and environment is spot on... while providing max DLI ... this is all we can do. Force feeding extra P or K will not change the plants metabolic rate... a good feed matches up with this rate of use... this is how you maintain a healthy plant with no deficiencies, toxicities or lockout.
If not max dli, more light can help. Adding CO2 to environment increases amount of light the plant can use per 24 hours cycle. This would allow you to increase light (which also increases DLI = daily light integral)
how many photons you can give without adverse effects informs about how optimally you are providing for your plant - including environmental factors like temp and RH%. Google DLI chart. even if you don't control all aspects, it helps understand how this all funcitons on a biological/chemical level.
