Name this product...

[David]

There is a "light weight" cement that people use to make artificial live rock and tank decorations. I just can't remember the name. Suffering from CRS, please help.

[icemark]

I use Portland Cement. #3 at the ol Home depot.

To make it light, you need to mix it with CC and plastic shavings (go out to RidOut plastics or San Diego Plastics in Kerney Mesa and ask for their sweep up) Or pasta.

Not more than 5% pasta if you use that. Not more than 20% for plastic, or the rock gets crumbly.

for dry mix:
2 parts cement, 2 parts CC, one part plastic or one half part Pasta, and the appropriate water.

If you use Pasta you will need to soak for at least 12 weeks for it to dissolve correctly.