concrete cow-pies (DIY live rock)

I bit the bullet today and tried for man-made live rock. I figured I would cure it all through June and July and set it into my sump and fuge at the beginning of August. After it's been under the tank for a while, I would contact a local reefer who collects pods, and I would be able by September to put a Manderin Dragonette in the tank. I'm planning three-four months out because I am just too impressed with the looks of that fish to turn it into a "Floater".

Also, I read somewhere that live rock is still better at nitrate removal than any Macro algae or Mangrove.
So I'm going to load up my sump with live rock, and see if it helps get "Algae Acres" under control. :

Two comments: (okay, three...)
1) I need a cheaper source for the Oyster shell used in the recipe I'm using!
I paid a buck a pound for something that should be twenty cents a pound without the fancy packaging.(Any help here would be appreciated).
2) I am an ARTIST! ...so why do all my new rocks look like concrete cow pies?
3) I tried adding water softening salts to the mix to make the rock more porous. I opened the bag from the bottom and found some really BIG chunks. I think the salt will disolve the rock before it even dries! :-[

But nothing ventured, nothing gained, RIGHT?

 

the salt pellets will not dissolve in the cement.it will dissolve while curing.even the salt inside the rock will dissolve in time.i would'nt use the shells in the cement .it creates sharp rocks that cut your hands up.just use cement aragonite sand and salt pellets.but its your rock so have fun.

 

have you seen the reverse mold deal in sand? Get some bags of aragonite and do it up.

 

Geothermal Aquaculture Research Foundation Home Page

 

I used the crushed oyster shell and like how my rocks turned out, although you do have to be a little carefull. I've never been cut by it but I have received a few good scratches. Try a ranch supply type store or a feed store for the crushed coral, it is a feed additive for livestock. If I remember rights I got a 50lb bag for about $12. Also try cutting back on the amount of water your using, try for the consistency of cottage cheese but a little drier. I used 5 or 6 parts crushed oyster shell to 1 part Portland cement for my rocks. I then used more oyster shell, damp, to make the mold. Never tried the sand but I bet it would work the same. I also used 1 inch PVC pipe to make tunnels through my rocks. If you leave it a little long it's fairly easy to pull out once the rock is cured. Some people use macaroni or someother type of noodle to do the same thing. Be creative and have fun.

 

Yes, but the cost of either argonite or oyster shell is the present problem. A sand or shell mold requires finding larger quantities than 5 Lbs bags.

Some one mentioned crushed coral from feed stores, I'll look into that.
But right now, the cow pies will do, it is going into the sump and fuge, not the display, thank goodness!

 

tuffa also helps alot cause of all the pours in it.the more pours,the more denitrification goes on.the cement rock will do nothing but fill up space and give things something to grow on if it does'nt have holes or pours in it.i decided to make cement rock because i needed something the shape of tonga shelf rock to make caves and well shelves.which is wayyyyy over priced and has almost no beneficial life on it.