side-effect of salt on curing cement

[wooden_reefer]

I am making "live" rock.

I read from someone that salt should not be used as it interferes curing of cement.

I know that salt is used on the surface of concrete as decoration or antislip.

Does anyone have an opinion?

I just made a batch with salt (to make it more porous if the salt is of small crystals and more natural looking if the salt is of large crystals).

I hope I'll be OK.

[sunkool]

It will be fine. I have made over 500lbs the same way.

[badfish03]

Just make sure you add the salt at the end after mixing the cement that way it has less effect on the mix.

[wooden_reefer]

I ask because it suddenly occurs to me that the cement is actually curing with saturated brine, the kind in the Dead Sea.

My thought now is that adding more small crystal salt is an excellent idea. It increases the overall size of the rock with reduced weight and increased porosity, which will make it more "live" in the future. I am adding quite a bit. By volume: one part cement, one part sand, two parts crushed coral, one and a half part small crystal salt. I figure that the salt is not really a part of the mix, as it won't dissolve pass saturation. With so little water, only a small fraction of the salt dissolves.

Being able to make my own rock and means to make realistic rock work have been a much needed advancement for me.

I am making foot high terrances. Corals that need the most light will be placed on top of the terrances. Even though my tank is 24" deep, the light requirement would be reduced. I may use just two 175W instead of 250W MH. Still thinking about it.