It seems like that, both of your apps is doing full backup of your external hard drive, so it is easily been full. Well, the thing become easy if so, and what you need now is a backup software which can do incremental backup so as to backup only added files. So I'd like to recommend you AOMEI Backupper, it's free and you also can use it to set a schedule job.
I've got a Seagate Slim 2TB external for backup. I have the option of using Seagate Dashboard for scheduled backup or I can also use the backup app provided by Norton in my Norton 360 application.
The issue I have is that both of those applications tend to fill up my external drive with MASSIVE backup files.
I'm looking for a Backup Manager that will simply backup my NEW files on a regular schedule. I can't seem to satisfy this with either of the 2 applications I've mentioned.
If someone could kindly instruct me on how to set up either Seagate or Norton to perform as I'd like, or suggest a completely different application that would work, I'd appreciate it.
Thanks in advance -