[pdfb55]

I am gonna try and do the cement base rock stuff based on the plans all over the internet. My question is, i have a ton of shells, can i use crushed up shells instead of the argonite sand?
Thanks

[underseaworld]

I have used crushed oyster shell for mine. Pretty much anything that came from the ocean can be used in hole or pieces. You can go to the feed store and get a very large bag of crushed oyster shells for just a couple of bucks. I will be starting a 300 g tank starting in a next few months. I plan on coating the back glass and side glass with the mixture. I think this will give the tank a good look.

[john_auberry]

i used oyster shell

[The R/C Man]

Hey guys!

Well from what i have seen coraline algae doesn't like to grow on the homemade stuff. So if you are hoping for it to look natural it may not. Also the homemade rock is not as porous as the "live" stuff and doesn't provide filtration. However it does save lots of cash..... Just wanted to open up some thought on this subject......

[underseaworld]

There’s a lot of tricks out there that will make the rock more porous…
I have used a drill. Which I found that takes a lot of time if you are making a large sum of rocks. I have also found that if you use rice crispy or boiled macaroni will also work. It is easier to mix the rice crispy/ macaroni after the mixture has been made. Another words I figure out the size of my rock I want to make in my molds and then mix the rice crispy or macaroni in it. During the curing process of about 6 weeks the food will have dissolve away. And at that time you will have plenty of holes in the rock. If you place the rock at the bottom of the tank and place the live rock on top the creatures will migrate down to the bottom rocks. At least that is what has happened in my case. I also use a protein skimmer during the curing process. All the base rock have a lot of creatures on them. Bristle worms, spaghetti worms, seem to love the rock. The coralline algae does not stay on the rock for long because my urchin loves the stuff….

[BubbaWPB]

Originally Posted by underseaworld

... During the curing process of about 6 weeks the food will have dissolve away. ...

Do you do the full 6 weeks of curing in saltwater? Or do you do the first few weeks in tap water just to leech out the nasties from the cement?

[The R/C Man]

The rice krispies thing is a good idea. Never heard of it before....

[icemark]

Originally Posted by The R/C Man

Hey guys!

Well from what i have seen coraline algae doesn't like to grow on the homemade stuff. So if you are hoping for it to look natural it may not. Also the homemade rock is not as porous as the "live" stuff and doesn't provide filtration. However it does save lots of cash..... Just wanted to open up some thought on this subject......

Actually if the rock is properly cured, I have found Coraline to go even better on man made rock.

and to get a more porous rock, mix dry shell and twist pasta in with the cement/shell/sand mix.

But the big key is curing the rock. It needs to be submerged in regularly changed fresh (for strength) water for about 6 to 8 weeks or you will get a major PH spike (which will slow to stop any coraline growth). Curing in Saltwater will result in softer rock that breaks much easier. For curing the best way I found was to use an older toilet (that has a 3.5 or 6 gallon tank) and just put the rock in the tank. Every flush will rush new clean water onto and over the rock.

[BubbaWPB]

$%#^&*! ....and I just took that old toilet that had been out in the front yard for a few years to the dump earlier today!

[underseaworld]

I set up a 5 gal bucket to make my mixture. When I made my rocks I made about 150lbs of rocks. In the 5 gal buckets I would place 20 cups of oyster shells and then mark the outside of the bucket. This means I do not have to make any more measurements for the oyster shells. Just fill to the line and then add cement and water. Once the oyster shell in the bucket is mixed. I then use a rubbermaid tub with sand to make my molds. At this time I put the mixture in the mold and then add rice crispy/macaroni. Once dried I then place all rocks in a play pool with protien skimmer. I would also flush all the water out of the play pool every other day with a garden hose. This way I am always flushing all the nasties out of the water also. After 6 weeks or so I then put some Novaqua into the water to take out the chlorine out of the water. I let it work through out the play pool for an hour of so and then add the rocks to the tank. This has worked great for me.

[Little fish]

anyone have a good link to good instructions for makeing the rock.

[PureVirtual]

http://saltaquarium.about.com/gi/dyn...b3%2Farago.htm

found this link a while back

[underseaworld]

Here's another site to look at.

http://saltaquarium.about.com/od/liv...ndsandfilters/

http://www.reefs.org/library/talklog...er_052498.html

[Little fish]

Thanks

[pdfb55]

thanks
I think i'm going to make some soon and let it cure until the end of march, which is when i plan on starting my tank anyway.

[The R/C Man]

Some good info on the rocks...... I have never thought to much about it before now but there seems to be potential there.....

[pdfb55]

also one last question,
i've heard alot of mixed opinions on lava rock, it is ok or bad to use?
thanks

[vtec si]

Originally Posted by pdfb55

also one last question,
i've heard alot of mixed opinions on lava rock, it is ok or bad to use?
thanks

IME it can leach out things you do not want in a reef tank!

I also remember Scubadude had a thread on how he made his rock. You may want to PM him.

Martin