If having less crowds is an important consideration, when is the best time to visit Brooklyn Aquarium?
(which times of year - preferably summer, which days of week, which times of day).
What mkennedy said in his comment is right.
This google search shows you how busy they think it will be over the course of the day.
Looks like trough the week it's pretty even.
I hope it is the aquarium you are looking for.