How long does a turtle need to adjust to a new tank?

It depends on whether you just got this turtle or you are just giving him a new enclosure. If he is new to your home then it will take about a week, but it depends on the turtles character as well. I would leave a new turtle alone for the first 2-3 days and then start handling him. But it will take about a week for him to get completely settled.

If your turtle is just getting a new enclosure then he will probably be awed by his new tank and get right to exploring. It will probably only take about 3 days for him to get settled.