The rocks can be submerged. Like any concrete product they'll leach calcium
hydroxide for a while. I purchase concrete coloring but since concrete
stains you can use anything with color. For instance if you wanted a "blue"
rock you could dye it with food coloring. That's why people put sealers on
their walkways so that someone dropping a coke wont ruin your walkway. You
can't use normal paint because the concrete will make the paint peel over
time. Once the calcium hydroxide is leached out of the concrete it would
cause any problems. Calcium hydroxide is what raises the PH of water when
you place concrete into it. It's PH is about 12-13 and will quickly raise
the water's PH to that if there's not enough water to dilute it.


"Mark T." wrote in message
...
Hi Sam,
Do you recommend fully submerging the rocks of the
type you make? What type of paint would you suggest
for that type of application? Will the concrete cause
problems with fish / plants over time?
Thank you,
Mark

"Sam Hopkins" wrote in message
.. .
The background was first made with styrofoam for the 3D shape and then
coated in concrete. Using a brush in a stipple motion made the texture.

What you cant see is the custom stand I made for it. The entire tank was
covered by the stand with the exception of the front glass. The
background
wrapped around the sides. This gave it a great "zoo style" apperance.

Sam

"Gene" wrote in message
...
I like that 20 Gallon XHIGH Cave. How exactly did you make it.



Sam Hopkins wrote:
It's pretty easy. Make a bunch of test rocks first though because it
is
something that takes practice. Check out all the concrete aquarium
backgrounds I made:

http://www.tiversa.com/concrete/

Sam

"stricks760" wrote in message
news:VRGVa.31975$Ne.31673@fed1read03...

Hi -

Still pondering about my waterfall. (1) Anyone with experience
making
fake
rocks? I've got a book or two, is it as easy as they make it sound?
(2)
I've read about chicken wire and concrete approach, and the
expanding
foam
approach. Any comments? (3) Doing ANYTHING involving chicken wire
on

top

of the liner sounds like trouble to me, comments? (4) All these
concrete
fake rocks, same issues with alkalinity as concrete in the pond
itself?

A ton of questions, but the fake rocks thing is sounding like a good

option.

But a realistic option?

Thanks!