Hempy...I am assuming perlite. I have grown hempy before, I remember having to pH like a hydro run. Also I had to flush it a lot cause it was suspect for build ups. Although I was running synthetic nutes at that time. Liquid Karma and Floralicious are great, and goes in my teas I brew. Dont know much about GH's lineup. How far off the bottom is the drain for your Hempy? I would flush it with water pH @ 5.8. Then give it a lighter feed. Do you always grow Hempy? Or you just giving it a test? Hempy grows are fun and they can grow fast and large. Just be careful of Algae!
Peace
FM