The substrate is just beach gravel, from the same coast as all the toher bits and peices and i is the same as I use in my freshwater tanks, except I didn't clean this stuff.
the rocks were just one that were in a rockpool, I pulled out that has seaweed attached to get a few little greeblies in it.
Yes it is all just rockpool stuff, and it just has a small internal filter on it, as I am quite close to the beach and getting fresh water is no probs at all for me.
B