that looks really cool, how did you make them?
My other half brought a big bit of green slate from the garden centre and chiselled bits off. I just overlapped a couple of pieces and used silicone to glue it.
The pebbles are a different story! Brought two bags from lfs, £3 each. I laid the tank on its side and just siliconed pebbles on. I tried having some sticking out more than other for a bit of depth. In hindsight I should have overlapped them a bit more so the back didn't show. I had some pebbles left over so I got a big piece of slate and built an ornament on top of it, a sort of tower. I left a big gap either side which Boromir loves hiding in! About two thirds of the way up I siliconed some slate on top and then siliconed more pebbles on top. This left a hole in the top so I put some sand and gravel in it and put a plant in the top.
Took ages, but I must admit I did enjoy it!
As for the other tank, I just brought the background and silicioned it on. I placed another piece at about a 45 degree angle from the back just to bring it to life.
And re-reading this, I've just realised I've got too much time on my hands!