/home usage mysteriously shooting up?

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http://crunchbanglinux.org – I was looking on the desktop and checking my /home usage on conky and to my surprise the /home had shot up 4gb recently for no particular reason. I didn't download any files recently that would even total up that large. My /home and / partitions are separate from each other. The last things I installed were python3 and cmatrix and I'm pretty sure those if any would mostly affect the / usage and both of those were small installs so that can't be it. Is there some way to check what happened without reinstalling? Oh one last thing, I'm running the 1st waldorf image btw. (HowTos)