Humic acid is an ingredient in several fertilizers, including the pure blend pro bloom, so you should be fine. I'd use it much lighter than the bottle recommends.
However, its primary function is as a soil conditioner, and I've always just used it when I flush, just a small amount in the final stage of the flush when you also add a small amount of complete grow fert.
So, my instinct is to just use it when you are flushing or trying to correct a lockout or salt tox situation.
stinkyattic Reviewed by stinkyattic on . Humic Acid... I'm a soil grower and have heard good things about Humic Acid. So...I just got some Soil Syrup (humic acid - 12%) and some MycoBoost (beneficial fungi) and am wondering before I add to my schedule, is there a specific time or stage I should discontinue use? Is it ok for flowering stage? Late flowering...? I use FF Grow Big with an occational jolt of Superthrive during veg. and Tiger Bloom for flower. I think it's too late for my flowering ladies right now, (6 weeks) but want to make sure Rating: 5