Did ddrescue to bigger drive - capacity didn't change

I have a tivo Roamio HD with a 500 GB hard drive. I think it started to fail, so I got a WD 3 TB WD AV-GP WD30EURX drive. I used ddrescue to copy the data from the old drive to the new drive. I did it with my MacBook Pro, using USB 3.0 to SATA adapters. Everything seemed to go fine. I put the new drive in the tivo and immediately did Kickstart 57 as it started up the first time. I got the green screen for about 10 minutes, then everything seemed normal. I restarted twice because the capacity was the same as before the hard drive swap. It shows a recording capacity up to 75 HD hours or 506 SD hours, with free disk space of 32 HD hours or 227 SD hours. Does anyone have any suggestions for using and displaying the new, extra space? (This is my first time posting here, and I post questions online rarely, so please excuse any mistakes or lapses in protocol here.) Thank you very much for any help you can give.