"Stories Guide to Raising Ducks" says a young duck will start to lay and then lay for 12 to 18 months streight. Laying that long can be hard on the duck. Besides getting a good rest from laying and new feathers, the eggs in the seccond lay cycle are bigger.
Day 1, remove extra light if you suppliment
Day 2 & 3, provide water but no food (i think free range but no pellets)
Day 4, feed free choice oats instead of pellets
Day 15, In addition to oats have seperate feeder with grower ration
Day 42, Gradualy switch back to layer ration over the following week