i am having a minor problem with TM and hopefully someone can help me i use 1 external tb to back up everything i back up about 725 gb if stuff and when i go to run my TM it tells me i only have 150 or so GB of space to back up the aforementioned 725gb. Maybe i misunderstood TM, but cant i back up multiple days without using the same size of backup? i.e. i back up january 1st, december 1st and november 1st and it wont need 2.175 TB of space? i hope that makes sense thanks for any help!