Yep, that's what I did in my previous tank. Works great. I also gaffer taped a cone (top of a coke bottle) to the top to make pouring the sand in easier. I found the sand clumped up and didn't drop down the tube sometimes, so washed it down with a trickle of water from the tank. Keep the tube sealed against the sand at the bottom, and then raise it once the new sand is washed down. That way it doesn't just fly all over when it reaches the bottom.