# Supplement C......hardener?



## Robnjo (Apr 17, 2007)

What is that supplement(white powder) that starts with a C and and it a type of Hardener?.....calcium or carbonate...or...? 
Its added for corals and Live rock....i think


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## Robnjo (Apr 17, 2007)

...Carbonate Hardness Generator, thats what I was trying to say.
so what does it exactly do?


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