Have you looked at the ingredients too? My discus (and other fish) get Omega One flakes as part of their diet, and the ingredients are vastly superior to a lot of the other foods I've seen: Whole salmon, halibut, seafood mix (including krill, rockfish, & shrimp), wheat flour, wheat gluten, fresh kelp, etc.
The other stuff? Fish meal, wheat flour, corn gluten meal, brewer's dried yeast, wheat germ meal, soy protein concentrate, fish oil, shrimp meal, fish protein concentrate, dehydrated alfalfa meal... crap, basically. The ingredients list is about three times as long, and it even has potatoes and rice!
The second one does have a bit more crude protein, but according to the ingredients it's soy protein. I'd check out the list of ingredients and choose the one that has the best stuff... whole fish, not meal, algae or kelp, and as little wheat and other products as possible. I read the ingredients on my dog's food and treats from top to bottom, but I wasn't aware that fish food could have just as much (or more) crud and fillers in it. Now I read all of their labels as well to make sure I'm not just feeding them what amounts to cereal.