My air fern gets no grain, just supplements in soaked beet pulp. Here are a few suggestions to help if yours objects to the less than super yummy flavor of many supplements.
To make it a bit more palatable I add a 1/4 tsp (more or less) of ground fenugreek powder. Uckele also makes a sugar free syrup to add flavor, or you can use sugar free flavorings for coffee.
You might also play around with consistency. Mine prefers a soupy meal (better to make a mess!) but others prefer a thick mush.
Add new supplements s-l-o-w-l-y to let them get use to the new flavor.