Not sure if its special or not, but simple Dishes from a agricultural store are best. I pay $9.99 for large 5qt bowls, $16.99 for 7 gallon bowls and $19.99 for 15 gallons bowls. They do not crack and make it easy to clean. They may not look like a Cave or Mountain but I tried those a decade ago and they are junk, break easy when cleaning and dangerous.
Any repair you make will either leak again or harbor a crack you can't clean that will grow bacteria. I'd just go to Goodwill and look for an appropriately sized crock or baking dish. Or look through your kitchen for an old Pyrex storage container.
You can watch for sales on the cool looking rocky "reptile dishes" but frankly I have yet to find one that is both sturdy and easy to clean.