Looks at the BRS videos..the tidal garden video. My first aquascape was all it took. If you crush rock (powderish) or use an oolite type of fine sand one the joints it's fine. We're talking close to mortar and pestle fine. Throw it in the joints...use the glue masters thin. Hold it for 10 seconds and you're good. Remember to flip it over and make sure your bottom joints are good...requires two people.