Thanks fetcher!
DeFeKt, ya, there are a couple of good articles on making your own rock. Lots of info on the
www.garf.org site (they call it aragocrete) and I found mine originally from
http://www.geocities.com/CapeCanaveral/Hangar/6279/RaiseCementRock.html.
As far as advantages:
1.Its more porous than most purchased rock if you build it right.
2.Its as cheap as cement and oyster shell
3.It can be made to the exact types of sizes and shapes as you like
4.It grows coraline algae fast with both aragonite or oyster shell base
5.And did I mention its cheap!!
6.After months in a tank, it looks the same as any expensive purchased rock.
Disadvantages are:
1.Can be dense and not very porous if you build it wrong (bad recipe)
2.Can be too porous or weak and will fall apart if you build it wrong(bad recipe)
3.Takes about 8 weeks to cure in freshwater that you must circular and change the water every 24-48 hrs.
4.Takes months to grow coraline coverage.
5.Takes a batch or 2 to practice to make nice forms and shapes for what you want.[/url]