That's odd your toads are not very active. mine are more active then even my American bullfrog and if anyone knows them they are always out and about. A 20 to 30 gal tank is sufficient for babies but when they start reaching 5 to 6 inches it is time to upgrade. A cane toad full grown will have a hard time even turning around in a 20 gal tank. You have to remember this is the largest toad in the world And rule of thumb the larger the toad the more space is required. Now they do not require as much space as an American bullfrog which will need A 75-100 gal tank I think a 60 gal may be sufficient for two full grown toads. Any more then that you will need more space.

Can toads do require a good amount of calcium so it is good to be supplementing regularly.

Something good to remember about the cane toad is unlike frogs they hunt with smell meaning they will even go after a bug that is not moving i have personally seen this happen on several accounts. Which is a good reason they have been found to eat dog food placed out in peoples yards making them a threat to pets. I wouldn't go feeding your toads dog food don't get me wrong. Unlike a pacman or a pixie which do not need a lot of space because they will just sit and wait for there food to come to them. Cane toads will go out and hunt for there food. Now as for pinky mice they contain more fatty lipids per weight then a more mature mouse such as a hopper. To much of this will cause obesity but remember these toads are more active then most other large bodied frogs so it will take a lot more to make them obese but none the less you don't want an obese toad. Also in my research on the nutritional value of mice, pinkies have been found to have a dangerous from of calcium deposits that can cause liver illness in frogs and toads. However the information on that matter was inconclusive. The hair on the mouse as mentioned many times in this thread can cause impaction in amphibians but with this particular toad impaction is much lesser of a threat then most other species but it is always good to be cautious. If feeding as treats once or maybe even twice a month a full grown mouse fed to a 7 inch cane toad, the risk of impaction is almost non existent. However if you staple your toad on mice the risk of impaction isn't a matter of if it will happen, it is when.