Hi Nessi and Welcome!
I agree with Orandabeauty, peas a couple of times a week will help with constipation and SBD (I have a moor that used to get it something terrible). Also sinking pellets are better for them then the flakes. Be sure to soak them a minute before you feed them.
*Edit : You might want to not feed them for about 3 days, then feed peas for the next few days. That will help with the SBD too.
I hand feed my fish Peas and Spinach every couple of days too, they like bloodworms, earthworms (cleaned and not to big) Dandilion leaves and all sorts of other foods. Heck theres even Oranges, broccoli, frozen krill, tubifix worms, its crazy the food you can feed your little fishies.
I hope that helps, oddly enough I was feeding my fish when I read this and they are fighting each other to get to the top for the next pea