Hand feeding when you can (frozen mysis at the end of a pipette). If you can find frozen (I have not had luck with dried) cyclops (Cyclop-eeze is no longer available), that could also be loaded into a pipette and squirted on them with some success (Mine was red so I could see a little uptake). You can also try adding amphipods in mass to the tank. Adding some floating seaweed might also help concentrate the food.