Cement Live Rock?

[Lynden]

Hello, I found a gnarled piece of cement today, and it reminded me of someone who somehow used cement as base rock, and then it eventually became live rock.

However, doen't cement contain acid? Or is there any other pollutants in it?

Any information would be appreciated

-Lynden

 

[andywg]

Cement is actually very alkaline.

When using homemade live rock (based on cement) you have to cure it in water as it can send the pH past 9 and well into double figures at the start. After 4-6 weeks it has usually calmed down and will not cause too many problems.

If it is just normal cement (made with sand and/or ballast) then it might not be great as live rock due to it being less porous.

 

[gopper]

iv been looking into this subject of man made live rock and iv currentley got a bit curing in water (should be ready any week now)

in every guide iv seen it has said that the cement just on its own is no good, it needs to be pourous for the bacteria to breed and live, if ya can get ur hands on some crushed oyster shell and mix a bit of cement with it (around a 25 % cement to oyster shell mix is what iv used) and it looks ok, still a little gray but it should be well covered up by the time its fully seeded. there is lots of info available on the net if you go to google there are also some users on this forum that use it and have had good results, if time is not a factor it may be woth ur while making some live rock (and plus you can make more intresting shapes,caves,boulders ect ect)

if ya still want to try ur piece of cement let it cure in the toilet cystern for a few weeks then put it in a bucket of water, test the ph of the water on the day you put it in then after a week test it again, if there is no change in the ph then it normally means the curing process is over and its time to seed the rock (thats what takes time !!!!!)

Cj

 

[Lynden]

Yes, yes, I did a little research, and I think my dad is mistaken! I can't blame him, though; strong acids can have the same effect on skin and whatnot as a strong base. I think that's how it works anyway B)

But I found full instruction on cement base rock on a website that came up as a search result.
http/www.geocities.com/CapeCanaveral/Han...CementRock.html
They seem to be VERY enthusiastic on cement live rock, and call it "a dieing artform beginning to revive once more," or such.

Thanks,
-Lynden

 

[SkiFletch]

Oh yeah it totally works, and you are correct, strong acids and strong bases pretty much have the same effect on human skin (not a good one ). Anyone who ever dives on man-made reefs in the ocean from shipwrecks or old WWII battlements dumped in the ocean will tell you that plenty of life grows off of cement

 

[BigIan]

cement is most definately alakaline as i was off work for 2 weeks when i had cement burns on my feet from concreteing with a hole in my wellies