1 tbls per gallon once a week in veg will help the good microbiotics in the soil. Which in turn help the roots and keeps them from getting fungus etc.I don't start using it until 3-4 weeks of flower, usually. I start with 1 tablespoon per gallon and end the last two weeks with 2 tablespoons per gallon.
If you do a good cure, No. If not, Yes.oohhh is it nessicary 2 flush?