Well its not pure but its like 99 % or something close enough. I bought all my salt from Lowes here is the link to the exact product I used
http://www.lowes.com/lowes/lkn?action=productDetail&productId=25656-113-25656&lpage=none
There are alot of different things you can do design wise. The salt also can be used as filler in your design like a cave or something just fill up the hole with salt and put the cement mix around it but be sure to make the walls of the cave thick so they don't just break apart. Then as the rock cures the salt dissolves and your left with a perfect cave or tunnel whatever u designed. It does take alittle time and practice yur first batch won't look near as good as your 2nd and 3rd or atleast from my experience everyone learns what works for them as they go.
Ohh another thing i just wanna remind everyone of the ingredients.
1. Portland Cement there are a few different types there all safe to use ( This isn't concrete this is a powder almost, if it has any rocks or other material in it you have the wrong stuff).
2. This will be your filler material (What gives the cement some strength) This can be Oyster Shell (Cheapest I've found and can be found at alot of feed stores around the country), Crushed Coral ( Never used it but have heard of people using it), Aragonite sand/gravel ( again never used it but most of the online recipes use it )
3. Rock salt ( be sure to buy extra salt to fill your containers with , I would normally dig out a design make my rock and then pour more salt over the top). This salt can be used over and over only alittle actually sticks to the rock. One important thing about the salt is get crystals not the pellets.
http://www.lowes.com/lowes/lkn?action=productDetail&productId=25656-113-25656&lpage=none
There are alot of different things you can do design wise. The salt also can be used as filler in your design like a cave or something just fill up the hole with salt and put the cement mix around it but be sure to make the walls of the cave thick so they don't just break apart. Then as the rock cures the salt dissolves and your left with a perfect cave or tunnel whatever u designed. It does take alittle time and practice yur first batch won't look near as good as your 2nd and 3rd or atleast from my experience everyone learns what works for them as they go.
Ohh another thing i just wanna remind everyone of the ingredients.
1. Portland Cement there are a few different types there all safe to use ( This isn't concrete this is a powder almost, if it has any rocks or other material in it you have the wrong stuff).
2. This will be your filler material (What gives the cement some strength) This can be Oyster Shell (Cheapest I've found and can be found at alot of feed stores around the country), Crushed Coral ( Never used it but have heard of people using it), Aragonite sand/gravel ( again never used it but most of the online recipes use it )
3. Rock salt ( be sure to buy extra salt to fill your containers with , I would normally dig out a design make my rock and then pour more salt over the top). This salt can be used over and over only alittle actually sticks to the rock. One important thing about the salt is get crystals not the pellets.
