feeding behavior

Hey all. I introduced some fish into my 55 gallon tank. I put in 6 zebra danios, 3 juli cories and 3 schwartzii cories. I immersed the bag they came in in the water for about 30 min and added a little bit of my tank water into the bag water at about 10 min intervals during that time to let them adjust (did that via sarynge (how do you spell that?)) . After 30 min, I strained them from the bag, put them in the tank and let them do their thing for about 10 or 15 min. Next, to help them cope with the stress I gave them a pinch or two of food. Now, here comes the question; I am feeding them tetramin tropical flake food. The danios grab the pieces and then spit them out. The cories seem to gobble up the flakes but then eject them through their gills. Is this normal? Are they just not hungry? Is tetramin just bad fish food?

I'm planning on getting some spinach to feed the cories. I'm going to blanch it and weigh it down and see what they do.

Thanks for the help.

Thanks guys. I have plants and rocks/caves in there for them. The danios seem to enjoy picking on eachother and the cories school together (two different species) except for one. One of my julii cories is just sitting there on his/her own. Don't know if that's something to worry about. Everyone else is up and about. I'm going to leave the piece of blanched spinach in there until about 10 or 11 tonight (EST) then I'm going to take it out. We'll see what happens.