I am concreting the left hand side pile for real.
About 13" wide, 16" deep, 14" high. Steep pyramid.
The plan is to put mostly softies on it, so goes a bit closer to the surface.
The base layer:
I used way to much concrete for the base. Oh well. It is strong.
I decided to put it on eggcrate. Mostly to keep things from moving around as I built.
Some thoughts:
1) I really like a conglomeration of all sort of different live rock.
It allows for some interesting forms.
Also, it allows for you to build coral mounts that stick out, for example on a piece of big stag.
2) Using lots of little pieces is great - but very tedious.
Other than a couple of pieces, this is all made from rubble.
Doing so, you can really build exactly the shape/tunnels/whatever you want.
3) Fast set concrete is a curse and a blessing.
Again, very tedious, since you do one rock at a time.
But, you can basically keep going non stop. Working around, the previous section will be completely
hard, so you can connect to it without breaking the old piece loose.
Tend to waste concrete. Hard to mix exactly what you need every time.
4) Those cheap sponge paintbrushes are great.
Good for soaking rock with the glue/water mixture, for adhesion.
But key - they are great for pushing the concrete into the nooks/cracks, and smoothing/texturing it.
You get a solid joint, plus less visible.
5) Probably should have done bigger caves.
They are pretty big, but small relative to pile. Although I did want the end to be a bit more solid.