DIY Base Rock. Anyone w/ experience?

[beginnermatt]

I tried to make some DIY base rock with mixed results. The mix was 5 parts agranite sand and 1 part portland cement. I did this and let it dry for two days. Today I inspected it and noticed that the rock is on the brittle side. It does hold, but I can snap it with some force. Does this sound like I need more cement such as a 4:1 ratio. I now have to cure it. Any advice would be great. Thanks.

 

[tgfrench]

Sounds like you could have used more portland cement to make it harder. Though this does make it more dense also. I used the carbi-sea agro gravel (4 parts) silica sand (1 part) coarse oyster shell from oyster roast (1 part) and portland cement (1 - 1 /12 parts) I like my rocks a little more on the coarse gravel side. It makes them a little more porous, great pod dens . I used the rec. posted at the garf.com site and modified it to suit my tastes.
Be sure to cure it out for 4 -6 weeks. check its ph during the end of this period. If its higher than your tank then hold off putting it in the tank once the ph drops you are good to go.
terry

 

[jacknjill]

tgfrench, i noticed you are in winston-salem. as in NC?

 

[tgfrench]

yep jack winston-salem nc

 

[jacknjill]

wow youre right next to me. im in clemmons

 

[tgfrench]

yep sounds like it. Did you know we are trying to set up a local reef club? A few of us got together 2 weeks ago. You can find us on yahoo groups Piedmont_reef. Hope you will join us there.
terry

 

[betacrash]

Im getting ready to make my own rock too. What I have read so far is that if you use an airstone while you cure the rock it will make it a lot harder.

 

[jstrong]

i used to make ornimental concrete and if you were getting cracks or the items where breaking it normally meant to much portland cement (or not enough sand)