I personally don’t use Stash Blend in a reservoir; I water it in once every 1-2 weeks @ 1/2 tbsp per gallon of water. Some growers have been using Stash Blend in their DWC setup with success at 1/4 dose. With that though, the water is moving at all times; I worry if it’s in a reservoir without a mixer then some of it may settle at the bottom? Not sure, but the Formulation Chemist who helped create Stash Blend recommended using it within 24 hours after mixing in water. I wish I had a better answer for you.

A potential solution might be to burry the stash blend under the blumat dripper. Only issue with that is it doesn’t spread well. Another solution would be to just sprinkle it on dry and then cover the top of your pot with cardboard directly on the soil and let mycelium and bacteria do the work for you.