I didn't even need to turn it down, just aimed the pipette and let fly, which is what I've been doing with the granules. (They are sold as betta food, but are far too small and they sink - go figure? But they're carnivore food, high protein, high meat content. I use them for fry food because they are suitable for fast growing fish, very small and very cheap.)
Anyway, he is now vanishing frozen bloodworm with enthusiastic assistance from the guppy. So fingers crossed that he gets past this. Poor, neglected little goby.