Okay, and with acclimation; you added a bit of new water to his container every few minutes or so for a while? Just wanted to make sure so I can get the full story
Okay, what size is this tank and does it have a filter? Do you know about the Nitrogen Cycle? The cloudiness is a Bacteria Bloom from your Cycle trying to start, you can get rid of it with water changes yes but it will eventually go away on it's own.
At night cover his tank with a towel/blanket, the pure darkness will help him stay very calm, darkness just calms fish right down so he'll be feeling great when morning comes!