Foam / Cement cave pt. 1

I started this project about 5 days ago.
I'm building a network of caves for my clown loaches.
What I've used so far-
1 20 oz spray can of Foam Sealant. - Touch n Foam Original. ($5).
2 bags of Balloons- Twisty and Assorted shapes. ($4).

I used the balloons for my cave mold.
I was just experimenting, but here's what I did -
I twisted together 2 twisty balloons for the bottom.
Then I started spraying a few layers of foam, just on the sides for the bottom of the walls, and all the way around the balloons for cave holes. It’s hard to explain.
Then I stacked a small balloon on top of the twisty balloons, and then proceeded to spray more foam to build up the walls.
I stacked one long balloon on top of the other balloons, and then finished spraying the rest of the foam to finish the walls and the ceiling of the cave.

This entire process took me about 5 minutes because the top of the spray can broke and wouldn't stop spraying. Not what I wanted. It looked like a mess. At the time, I didn’t take pic’s because I thought this project was a lost cause. In the attached file is an example of what it would look like with the ballons.-

part 2

After several hours, when the foam started to cure, I popped the balloons and started carving. The mess was starting to look better; I also drilled a few more holes in the cave and carved away for a few minutes at a time for the next few days. What I ended up.

attached file is Front view

Attached is the side view

Attached is the Back view

attached is the right side view

part 3

The next process is to waterproof and weigh down this cave.

What I'm using for this is-

Quickrete Quickwall- white 50# bag. ($12)
Quickrete Playsand- 50# bag ($2.5)
Quickrete Cement Color- I'm trying out red, brown, and charcoal. ($5 each)

I'll post more pics and details when I'm finished.

part 3 cont

I finished the 1st coat of cement on the inside of the cave.
I used
2 cups water
2 Tablespoon Brown cement color
4 cups Quickwall
2 cups sand

I mixed the Brown cement color with the 2 cups of water, and then stirred in the Quickwall Cement and Playsand.

As I was troweling the cement on the cave I started having flashbacks of my pastry chef days. The Cement started to look just like chocolate ganache. I started to think, then went to the kitchen to grab my pastry bag and a 6” palette knife. My nervousness of this project had just melted away, as now I was working with tools that I was familiar with. The only problem I’m having now is that I’m drooling on this cake, I mean cave. Piping the cement with the pastry bag helped speed things up and made the job a lot neater, thus the palette knife was great for working the cement around the cave holes. I’m done for now (until it dries), I just hope I used the right cement recipe, as it is still wet to the hand.
Attached is a pic of my progress.