Android Storage Grab I am having internal memory grab, typically eating about 3gb.  Similar to this problem on a tablet Something is secretly eating up my Acer Iconia A500 internal memory and I need help finding it

However my device is a Moto X second gen.  I though it might be device specific, because after a factory reset and then a reload, I find the memory grabbed sometime later, usually 3 to 5 gb.  

Then I saw the same thing happen for 1gb on a Samsung tablet with some of the apps I have on the Moto X.  So I am currently thinking that this is application specific.  However, without a rooted device I find few tools or methods which appear to be able to help me.  Hence my appeal here.

Any suggestions as to how to get to the bottom and resolve this?  Loading apps one at a time could take months, until they are all loaded and the problem pops up again.

I may have to root the device, and then I will look in /data for growing subdirectories.

Addendum 1.  I used another utility, DiskUsage, and saw that there was 5gb in system storage allocated.  It appears that this could be something such as logs or some other cumulative data managed by the system.  So it appears that I will likely have to root the device to dig deeper.
Force the reset and Grab to happen again... After it has grabbed the storage, use this command in Terminal emulator to find what has been added recently... go through them 1 by 1 ...

Also you can use Sort to Sort By Size, and locate the larger files on your Internal Storage... 

find /storage/sdcard0/ -mmin -1 (mins)
find /storage/sdcard0/ -mtime -1 (days)