For those that are feeding their bees in the spring.
There are 2 reasons you might decide to feed your bees 1 to 1 in the spring:
# 1 - If there is a risk that your bees have exhausted their food stores and are in danger of starvation.
# 2 - If you are wanting to stimulate brood production if you intend to split (for pollination purposes maybe) or in anticipation of an impending nectar flow you are hoping to capture.
There is no need to feed if your bees have resources, enough to sustain them till the first nectar flow. I have been feeding fondant to hives I consider to be light but the rest are fine. I do not intend to split so have no need to boost brood production artificially. Why create work when it isn't necessary?