That is a good question, allrollsin.
Depending on your water source, you may or may not have enough Ca to fill your plants' needs, in which case you will have to add a Ca supplement. This isn't always listed in feeding schedules, especially for soil grows.
So keep an eye out for yellowing low leaves with irregular tan blotches on them.
stinkyattic Reviewed by stinkyattic on . Botanicare Feeding Schedules? Hey everyone I know Pure Blend Pro Grow/Bloom are well-respected ferts so I picked some up (along with some Cal-Mag). I have to yet start using them, and in the meantime I'd like to find out what you all use for feeding schedules with these little guys. They'll be under 400w HPS in soil. I'm aware of the necessity to dilute the ferts, but by how much and at how many weeks/months in do you change it up? Thanks everyone. Rating: 5