I also read to used rock salt in the mix, I will be trying that next time
too.


"Tidepool Geek" wrote in message
...
"skozzy" wrote in message
...
I have made 1 rock so far. Using the same methods. I went to the
hardware
store and bought a bag of white concret, then mixed it with crushed
coral
at
a mix of 1 part concret and 5 or 6 parts of crush coral.

I havn't looked into any other gear to use inplace of the crushed coral
yet.
I guess one day I will. Crushed coral isn't cheap, well not here anyhow.

Howdy,

If you have access to a feed store (farm not pet) you can get crushed
oyster
shell for far less money. [For those of you non-4H club folks, crushed
oyster shell is sold as a feed supplement for chickens.] Typical analysis
is
in the mid 90% range CaCO3. Use the same 5 to 1 mix. The resulting 'rock'
may be somewhat less porous than you get with crushed coral but that can
be
remedied by adding a small amount of broken up pasta to the mix; during
the
underwater portion of the curing process the pasta will dissolve leaving a
bunch of tiny channels for better water penetration.

I can't remember where I first heard of the oyster shell alternative but
the
pasta idea used to be on the GARF site (maybe it still is).

Frugally yours,

TG