You would need to see a soil test on the various inputs. For example, compost or worm castings can be high in K or Mg or nitrogen could be in the form of ammonium vs nitrates depending on how aged it is. All of these things play a role in determining what other nutrients are needed to reach sufficiency for your grow cycle.yeah, so the soil is used Island Blend from High Powered Organics, and im adding some high quality worm castings and what ever else the soil needs as time goes. Do you reccomend any kind of application rate for these specific amendments?