i guess we do not really know what you mean by food sources. generally speaking if you have gotten good LR then you should have pods, which are a great source of food. the problem is most people add pod eating fish before the pods can really get going. do you have a refugium? this is a great place to grow macro algae for those herbivores you may want. if you want to do this make sure you grow algae that the fish you are keeping like to eat. once a month or more often depending on how quickly it grows or the size of the refugium you can harvest and feed to the fish.