Do you be curing as in setting hard or the time it takes for the alkaline to
dissipate ?.

I was going to use it so after the rock had set and you put it in water the
salt washes away and leaves the rock with many small holes, good places for
little creatures to hide.


"CheezWiz" wrote in message
...
I have read elsewhere that salt can inhibit the concrete curing process...

"skozzy" wrote in message
...
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