materials for making live rock

[crook280]

i was wondering why/if you have to mix the concrete with caribi-sea sand? in rc there is a thread about using pulverized limestone as a substrate, and people do use linestone in their tanks, so can you make the rock with it to?(if you need to mix it) i guess i don't really see the reason to mix with sand. one more question, can it be any type of sand. here in texas, the good stuff is far and in between.(atleast for me) thanks for the help

[dskidmore]

Limestone is chemically similar to carib-sea sand. The sand is alot easier to work with, and gives the stone a nice texture. Some people have used crushed coral instead, also being calcium carbonate.

The purpose of the sand is chemistry, texture, and color. If you use a diffrent sand, you will have the biological benifits of live rock, but not the buffering benifits. You may have to do something else to offset the alkilinity of the concrete.