I made all teh rock in my tank using Oyster Shell and #10 cement. I left them out side in a kidy pool for a few month. I think I made them in Feb. and placed them in the tank in June. Make sure to change the water at less weekly. I also gave the rocks a 50/50 vinegar and water mix twice during teh process. Man does it fizz the first time. after the fresh water I just placed it in a bare tank, with sand and a few small LR pieces. I had a high PH for three days or so, then it was normal. This has been two years now and the rock looks good in the 33g and covered with coraline.

here are a few pics when I changed out the playsand for crush coral over one year ago.

http://img181.imageshack.us/img181/1446/10001084hc.jpg

http://img181.imageshack.us/img181/4853/10001149iu.jpg

I have DIY'd rock myself and.. after I was all done I prefered liverock. :lol:

I found the crushed coral and aragonite looked close to LR just without any colour.

OMG, that is probably the funniest, but most brilliant, thing I have heard in a while! :lol:

Great idea. :D

haha i've heard of doing that as well! It also saves you a little on the water bill as you're actually flushing less water!

Hi,

I have made my own reef base rock before (argonite and portland cement). But I stop making them once I found out about Caribsea's Reef rocks. They are pre-crush blocks of argonite and its about $1.25 a pound from J&L. I have used them for about 4 years in my tank and they look just as cool as any live rock that I have from Fiji. They take about 6 to 12 months to fully seed and cover with coraline.

- Victor.

With my experience I used both aragonite and crushed oyster shells. I found with only the oyster shells the cement wouldn't stick to very well and the final product was very brittle. I added some aragonite with the oyster shells and it made a great product. Add a little rock salt and you'll have lots of caverns.

I did have a few brittle pieces on my second bactch with just Oyster Shell. I think the trick was a little more cement and wetter made it work better. Also remember that the longer it is most the stronger it will set. I took them right out of the mold and placed them in a kiddy pool for month. THey are very poress and very strong.