What I did when I move is I took out all my decorating rocks, bogwood, and filter. But keep my plants planted. Then remove nearly all water, only enough to the fish submerged in water. Of course, I keep as much of the original water in buckets as I can. It's much easier to move for smaller tanks; I have a 10 gallon and a 40 gallon. So as long as you try to keep the tank as light as you can, it should stay strong enough to hold your gravel and a little water and you don't have to fish them out of the tank. Of course, if you have too much gravel, I would suggest take some out. Another thing to watch out for is to lift from the edges and try not to press in the middle bottom of the glass; make sure the weight is lifted evenly. Also, although the 10 gallon you may move by yourself, it is a lot easier to get a friend to help out. Most importantly, plan ahead. I forgot to setup the stand so I have to lift it twice. Try to get the tank last and get it in one move. Even if you are moving one block I still recommend using a car, the backseat should fit your 20 gal.