I feed my fish a dozen fathead minnows every third day, but I have a FW tiger muskie tank so you probably don't want my advice. Seriously though, I have had many freshwater tanks and set up my first saltwater tank a month or so ago. As with everything else, there doesn't seem to be any one way of feeding your fish that will work. As long as you are getting ammonia spikes I would assume that you aren't feeding the fish too much.