I have found out that the fish feed the best during low light conditions or low sun angles, even better if there is shade on the water. I have the TH feeder set to feed 45 min to an hour after sunrise and about the same time before sunset. If I throw feed at noon I still have a feed response, but nowhere near as good as early/late.
Re the short time after sunrise, you obviously aren't concerned with low DO levels? I have heard people warn against very early feeding for this reason.
