Why 1-2 Lbs per gallon. What happens with less?

What I did to keep rocks from falling down was make a stand out of pvc and eggcrate and put it in with and inch of sand over it so you cant see it. That way I can set you rocks on their and they wont sink down.

 

Manipulate it by hand a little. Do the pieces of sand seem cemented together? If so, you could have accidentally added a Calcium supplement too quickly causing a precipitation which glues sand together.

Nassarius vibex live in the sand and don't climb the glass. A lot of other whelks are improperly sold as Nassarius because they look exactly alike. Here's a great article. Do You Know Who You’re Dealing With? Get to Know the Real Ilyanassa obsoleta by Mike Greenemeier - Reefkeeping.com

LOL