Yes you can do that. You'd need to partition the library so you had one slot per partition and then point each days backup to the particular partition. To do that you go into Devices, select the library, and if you right click the library you'll see an option to setup the partitions.
Now in terms of it being a good idea... For ease of use I'd have to agree that it makes sense, however from the disaster recovery point of view it's not necessarily the best idea. To make sure you have a decent DR setup you want to remove the tapes after they've been written to, and either take them offsite or at a minimum put them in a fire proof safe. Otherwise if you have a fire or some other disaster that destroys your tape library, your most recent backup tapes will be trashed at the same time.
