He really looks completely normal in that little cup and swimming around. If he stays at the bottom a lot like you said and how i understood he was more active before, you can keep him in the cup and try to do water change tomorrow like you did today see how he doing. Try to feed him. And give us update.
I would put him tomorrow in his tank though and see how he doing. Remember to acclimate him to new water temperature/chemistry by adding new water in his changing cup. Then you can just put him in the tank. And see how he doing, if he still at the bottom of the tank.
What kind of pellet do you have? Did he eat them at the beginning. Sometimes new bettas really takes time until they start eating. I know some pellet are big not sure what kind are you using.
I like Aqueon Betta Food,New Life Spectum Betta Formula if you can find them. New Life though not floating and if he is not eating they will sink to the bottom right away.
It good to have aquarium salt on hands just in case you need it.
Cover container with lid bettas can jump...
Last edited by BETTACHKALOVE; 09-12-2012 at 08:09 PM.