No experience with red tail, but all adult fish that I know should benefit from "fasting" them 1 day per week. Also, most fish can go without food for about 1 week ... of course, they will start to be more territorial.

Just like humans, our baby needs multiple feeding per day, and we can survive with 1 meal every few days. We will not be in our best form, but we will not die. Of course, we prefer 2 meals daily. Same concept with fish.

That said, I don't think your fish will suffer greatly with alternate day feeding. But I'd still suggest smaller DAILY feeding.