Fibreglass jet tub as stock tank

Hello all,

New to aquaponics and the community. Have just started the quest for system components and came up with a beautiful deep, oval second hand jetted tub for use as a stock tank. Being a used tub it has also been cleaned with liquid cleaners over the years. Does anyone have experience in sanitizing these tubs in order to provide a safe environment for the fish?

Dave in Ottawa, Canada