Compression Options for BackUp Exec 3600

I am just starting out learning about our BackUp Exec 3600 and I have found that the 5TB onboard storage will be quickly used up. I am interested in a compression solution. Since most of what I am backing up will be Virtual Machines, there are few duplicates for the "deduplicating" scheme to handle. So, I need to know what my other compression options are. I am working my way through the eLibrary but it is farly vast and there are a few direct questions like this one that I haven't come across yet and need answered.