don't feed the red worms because when they are molested, they secrete very nasty mucous that the frog will not like. Earthworms can be fed though and be sure to feed ground up soy beans, this will put some meat on the worms and cornmeal isnt very nutritious. Dechlorinated tap water is OK, but try to use natural spring water if you can. Many bottled waters still have the chlorine and minerals that may be beneficial for us but harmful to the frog.

I would recommend keeping him in a smaller tank though, possibly a critter keeper. pacman froglets
can get stressed very easily in large enclosures. A small critter keeper you would see at most pet stores is adequate.