I have used it. The plants seemed to like it quite a bit. I mixed it with some Ascophyllum Nodosum kelp powder, as this seemed like a combination that would happen in nature. One word of warning: Neptune's Harvest comes in a glass bottle, and is mostly emulsified fish guts. I dropped the bottle on the concrete floor of my basement, the bottle shattered and my basement STUNK. I suggest that you transfer the solution to plastic for safety and sanity.