I am going to be moving about 20 minutes away, I’m thinking about leaving enough water to cover the sand in my tank given it’s a 13 gallon. Good or bad idea?
If your rocks will stay put during the transport it could work. One fast break at a stop sign could cause a fast break in your 13 gallon.
I would suggest putting rock in a bucket, draining the tank (save the water?) put any fish in a second bucket, drive carefully across town and quickly reassemble could work. I have watched a store do this, they moved at night to minimize solar impacts during the move.