I know this probably belongs in the feeders section, but it's slightly urgent and the worms are for my Pacman.

I just received a box of 500 large worms. The box of dirt they came in is full of rock hard dirt clumps. The worms can slither between the clumps, but I doubt they can consume which I believe they need to live.

I'm thinking of filling a small tank with eco earth, transferring the worms and keeping the tank in the fridge. So I'm wondering, does eco earth have a similar vitamin and mineral makeup of standard dirt to sustain worms and keep them healthy for a month+? Do I need to but actual chemical free potting soil?