dreamie, can you give us more detail as to what you here?

thanks for your answer... and question :)
a bubbling rock is a water feature. I have seen these where they must have drilled through a large rock so the water can bubble up out of the hole but I have seen others that are perfectly round and thus must be artificially made.

I am looking for directions on how to make such a feature.

Chris

OK. I have never made a these hollow rocks but don't think they would be to difficult to do,I believe these are made by covering scrunched up chicken wire to the shape and size of the rock you want to make. You should try a search at the top of the page for 'hollow rocks', I just finished making 3 Spheres (see my recent post below)one for a bubblier, these are made covering an inflatable beach ball, and trust me a little more difficult lol. I buy small pumps at wally-world for these. It would be best if you get some experience make pots etc. first till you feel comfortable working with hypertufa, and be sure to read the FAQ's here first.
Would love to see your projects once you have them done. Wendy

I used leftover concrete to make a bubbling fountain.
I taped an upturned planter saucer in the bottom of a round bucket - the saucer was about an inch smaller than the bottom of the bucket. A stick was secured to the centre of the saucer. It's so long ago I'm trying to remember what I did, I'm sure I lined everything with plastic for ease of removal. Then I added the concrete. It looked fantastic when completed, the water bubbling through the hole filling the reservoir created by the saucer and trickling over the sides. Unfortunately I haven't a photo of it on this computer and have since dismantled it until yardwork is completed and I have a permanent spot for it.

We have also drilled through a bowling ball using a long masonery drill bit to make a bubbling ball fountain. You could do the same thing with a rock or a hypertufa rock, just take it nice and easy so you don't burn the drill out.

I've made a "bubbling rock" to look like an old mill wheel. Just get a 2" thick piece of pink insulation board, cut the board into squares large enough to accommodate the size "wheel" you want, cut a donut hole out of as many squares as you want height; then stack the squares to the height you want and fill in the hole with mix. 4" should be enough height. You can either make the hole in the center for the water to flow through with a small pipe while the mix is wet, or drill it after. You may want to line the mold with plastic, as cement sometimes sticks to the pink stuff

I've made several fountains with a hypertufa orb as the topper. It's quite primitive and beautiful with water flowing around it. I just used a styrofoam ball and coated it with several layers of mud at varying times, until I get the size I want. When I have the final layer, I give it a light wire brushing several hours later. After letting it cure for a week or so, I drill a 3/4" inch hole through the center, hook up the pump and tubing and viola, a "bubbling rock or orb". I have it pictured on the gallery side.