In fact, recycling is the same as relabeling. NW will just write the same or a new label and write a special pattern on tape which indicates the logical End-of-Tape (LEOT). This means that the previously written data is lost as the tape drive's firmware does not allow you to read beyond this point. With the next backup, this LEOT will be overwritten and a new one is written when the backup ends. Deleting the tape means that you delete it and its associated save set from the media index, but it will not affect the data on tape. You can re-add the index data with the scanner command. Recycling tapes after they have expired is IMHO best practice. Deleting media is usually not necessary unless you want to correct a certain scenario.    
Hi every one i have this scenario , 8 tapes for weekly backups cicle  (2 for each week) , use the same weekly-pool and expire in 1 month In this rotation   i reuse the  tapes but i relabel de set of tapes no get an empty set. ¿Is this the best choice or best practice? if I am wrong,  Wich is the best action and Wich is the difference between  relabel , recicle and delete tapes? Thanks in advance.
Difference between relabel, recicle and delete tapes