I say if the water is still above 55, say 60 or more, feed like once a day for a few minutes, or as much as they seem hungry for. Sometimes fish wiil let you know when theyve had enough. But if its more of a constant 55, either do every other day, if they seem a little hungry, once a day, or every other two days, maybe for a week and if temp starts slipping below that, stop. Make sure to try and feed them a good wheat germ, or fall diet, no flakes now, they need to fatten up as much as possible. Tetra makes a good spring and fall diet.
Hope this helps, dont overfeed either! Good luck!

crazy4koifish