While making my aquascape (thin glue and crushed rock method), at one moment i wasn't happy with a piece i did and tried to remove it. Couldn't break it off by hand. Grabbed a big hammer and knocked it off. It came off but not at the glued joint, it broke somewhere else.I wonder how long rocks will hold with those 2 methods and no support. I've seen thick rocks break while large thick colonies are trimmed.
It's solid as a rock if done well.
I did exactly what the Asian guy from the video did. Drench the gaps with glue, fill the gap with crushed rock, drench glue again, then again some powder, and the gaps are invisible and superstrong.
Don't be afraid to use too much glue and finalize with dropping powder on it which makes it invisible.