Agree, if you are wanting to stick your rocks together then use aquarium safe silicone. Fronts do well with Peacocks as they are rather docile. If you are wanting to mix in with nbuna then look at these being the smaller fish when introducing others. I have some Placidochromis and Nimbochromis in with my mbuna and they are fine. I have found that coral grot does extremely well as a fine substrate. Some people say it gets dirty but have not had this happen to me. Tanks seem to stay a lot cleaner a lot longer than when using stone chip.
I think the secret to building a rock formation is to place the correct ones at the base, those which will not just collapse when the fish dig out around them. Bury these down to the glass.
Am looking forward to seeing some pics once established.

I think the secret to building a rock formation is to place the correct ones at the base, those which will not just collapse when the fish dig out around them. Bury these down to the glass.
Am looking forward to seeing some pics once established.