At 54F the perch should be willing to feed at the surface. If they are not surface feeding, maybe try reducing the light intensity to almost dusk conditions. Also try softening the food and roll a few into small pea sized pieces and drop them into the tank as you stand back a little distance from the tank. Feeding fish will soon move higher in the water column to get food due to competition. I will send you the softening technique.
This evening, I managed to get perch and bgill to feed sparingly at the surface in water temps of 46F. Prespawn perch seem to be real hungry.
