how do you glue rocks??

[eli@fijireefrock.com]

There are many ways and product in the market to use but I found that FijiCrete to be one of the best to keep hardness and shape of the aquascape.Here is a video, a bit long but shows the work with FijiCrete
Youtube link (try not to laugh at the mistakes..lol.)
FijiCrete part1

[Dive_dry]

I used a fish friendly spray foam I got a a pond store worked great and it's fast took longer to designe then to glue

[Duckhams]

Acrylic rods and epoxy - https://www.bigreefdepot.com/Aquariu...ocks-s/125.htm

There's always a chance glues/epoxy's/cements etc won't hold or will crack, decreasing the stability of your rockwork. Drilling the rock and using acrylic rods is a definite way to prevent avalanches and potentially glass shattering rock crashes.

That being said, Eli know's his stuff with fijicrete, after all, he is the rock guy!