The "Add Nutrient" light on the AG3. I think it is just a matter of adding a pill.
I have big news. Hops seed #22 actually sprouted! It is a wild, hairy little thing. This was one I preconditioned in the fridge for six weeks like the directions said.
In other news, the tomatoes are doing great, and the nearby coffee shop is giving me all their grounds. Much future growth forecasted.