I've noticed light penetration seems to be a big factor with ice fishing. In my front pond even when it was well stocked I couldn't get much action on bluebird sky days even with some snow cover. The fish were there but they just weren't interested. Of course one would say they were conditioned to feed at low light periods which is when I fed them, but it seemed to be more than that. Normally I could get a fish to bite anytime in the pond by putting food in front of it's mouth but not on bluebird sky days.
It's almost like they get used to low level light under the ice and then when it gets bright they don't like it. Sometimes even with a lot of fish in the pond when I could see down and around a good distance they were nowhere to be found and apparently were down deep in the weed growth.
