For the best health, your not going to want to feed only one type. I recommend a mix of dry, live/or frozen. this is going to give your fish the best range of nutriets. Live foods aren't for everyone, but if you can get your hands on california black worms, that would be a very good food everyonce in a while. they are a bit fatty so not everyday. As for dry foods, I highly recommend staying away food brands which use a chemical called ethoxyquin. this is a fruit tree pesticide and not good for your fish. HikarI has some of the highest grade food and best. other brands not containing ethoxyquin include Aquaeon, Zoo Med, Hikari, and Red Sea. However, like I said above hikarI is one of the best out their and I feed all my fish hikarI now.
I feed my fish a mix of pellets and flakes...I don't buy the cheap stuff. Cheap stuff can lead to problems with certain fish...
With your plecos I would give them some boiled zucchini, they'll much on that, poop green and be satisfied for the rest of the week. Leave that squash in there and it probably be cone in a few days.
Awesome thanks a lot! I've heard a lot of good things about hikari. I'll definitely try out the zucchinI too.