I concur with what has been suggested. The brand is important though, as there are some issues with cories especially.
As you have a herbivore fish (Bristlenose) in with carnivore fish (Corydoras), you will need to cover both bases. Corydoras do not do well on herbivore foods (Ian Fuller has detailed this on his site), so I (having a similar situation, Farlowella being herbivore in with Corydoras) fed Omega One's Veggie Rounds once a week. There is algae/kelp in this but there is also whole shrimp and fish. I have been feeding this to my wild caught cories for over a decade now and while I cannot say they are or are not worse off, only once a week may not be too much of a problem.
In addition to the Veggie Round once weekly, Omega One's Shrimp Pellets are superb nutrition for cories. My Farlowella and Whiptails go mad over these too.
And for a third prepared food, the Fluval Bug Bites do seem extraordinary. This is one of the most highly recommended foods for cories on Corydoras World (Ian's site) and from the way my cories charge around digging these out of the sand I can see why. I feed them twice weekly.
Frozen daphnia once a week, along with frozen bloodworms, but the latter definitely no more often than once a week. This is not a particularly good food, it has little nutrition, but it does seem to be highly appreciated by the cories, so a treat once weekly.
