Sparse disk image bundle file WAAAYYYY too big

Hi everyone! I'm currently using a Time Capsule in conjunction with Time Machine AND as an additional external hard drive. I decided against using the drive with Time Machine and deleted all my old backups (using the finder window in the Time Machine program). However, no space was cleared on my disk; i.e., the .sparebundle file is still HUGE! I have a 500TB version of the TC, with about 100GB being used on the hard drive and 204GB being occupied by the sparsebundle file. Is there a way to reduce the size of the sparsebundle file? I had thought deleting the backups would clear the desired space.