Thank you for the advise!

In that case, I'd try to find a shop online that sells supplements and coconut fiber. Will be using paper tissue as a substrate as a temporary measure then.

The only earthworms I managed to find are those from the bait shop, so until I can find a clean source, I'll have to stay away from them.

The first tank mentioned is in inches, and the 2nd is in feet. And yup, it's LXWXH in both instances.

I'll update again when I have pictures!