When to shock ?

I've noticed a couple small spots of algae on the steps. I plan to shock it for a couple days. Is it better to shock in the evening , morning or does it not matter?

I think the best time to shock is in the evening because you don't have the sunlight consuming the chlorine. If you have algae though I would keep the chlorine level at shock level until the chlorine holds over night. This usualy requires testing the chlorine level 3 or 4 times a day and adding bleach back up to shock level.

Shocking at night after sun down allows the higher levels of chlorine above what your stabilizer can protect from sun to stay in your pool and do the best possible job.