Conflicting air cell sizes

First hatch for duck eggs (Cayuga and White Layer). A little more than half of my eggs are perfect or a tad large on air cell size (day 25) and the rest are small. What should I do? I know increasing humidity to slow the bigger air cell eggs, and low humidity and I read misting for the small air cell eggs. Any good way to do this in the same bator? Two lights and a fan, though I can unplug the fan.

Thanks!