sand cleaning

I was doing some research on sand sifters and was wondering if 20 gallons was adequate for a tiger conch and potentially if there were any more options to keep my sand looking pristine!

I am referring to this video he made It looks like a great idea for both cleaning the sandbed and performing water changes. However I have no clue how he got that pump to stay on that setup. I got the same pump as he did. I found a 1/2 in nipple that screwed into the pump but its only held into...