When did everyone switch baby to the big tub?

Hannah • 26, Mother to Oliver, Nathan, and Mia. TTC👶💙 💖

He’s almost gotten too big for the baby tub we have for him, so I decided to try and bathe him in the actual tub. The only thing that scares me is that he tries to stand up! I’m afraid of him slipping and hitting his head on the tub or faucet.. what age did you transition your babies? He’s 8.5 months btw