Sand for DIY rock mold

[Nick Rose]

Is it ok to use sand for the mold that the DIY rock mixer goes into? When I took the rocks out and cleaned the sand off some of it is still on the rock. Will this cause any issues when they are ready to go in the tank after the curing/kuring process?


This is the sand I’m using for the mold.

 

[AlexG]

What kind of sand is it? If its silica based then its possible it can cause some issues if it contains and impurities that are harmful to reef inhabitants.

 

[Nick Rose]

I don’t know if it’s silica based. I’ll have to contact them to see if it is. I’ll just have to work harder to clean the grains off the rock.
Is there any other sand that can be used? The reason I went with this was that it only cost $5 per 1cuft bag.

#2 Olympia Sand | Sand for Mortar and Stucco | Sandbox Sand | Lyngso Garden Landscaping Supplies San Carlos CA

Olympia Sand #2 is used for making plaster, mortar or stucco and can also be used for sandboxes. It is a more coarse material than Olympia Sand #1, which provides it with better construction properties. We sell both Olympia Sand #1 and Olympia Sand #2 in one cubic foot bags. Lyngso will...

store.lyngsogarden.com

 

[AlexG]

I don’t know if it’s silica based. I’ll have to contact them to see if it is. I’ll just have to work harder to clean the grains off the rock.
Is there any other sand that can be used? The reason I went with this was that it only cost $5 per 1cuft bag.

#2 Olympia Sand | Sand for Mortar and Stucco | Sandbox Sand | Lyngso Garden Landscaping Supplies San Carlos CA

Olympia Sand #2 is used for making plaster, mortar or stucco and can also be used for sandboxes. It is a more coarse material than Olympia Sand #1, which provides it with better construction properties. We sell both Olympia Sand #1 and Olympia Sand #2 in one cubic foot bags. Lyngso will...

store.lyngsogarden.com

If you put some of that sand in vinegar you can see if it bubbles. If it does not bubble then there is a good chance its a silica based sand. Unfortunately there is no way to know if it contains impurities that are harmful to reef inhabitants without testing it. The only sand I would say could be trusted would be a reef sand but it would not be as cost effective.

 

[TDEcoral]

I'm not convinced that silica sand causes issues. I used it long ago with no problems as have others. If silica were an issue, then wouldn't tanks made of glass be a no-go? Silicates are what can cause problems and they're not the same as silica. However, an aragonite sand is the best way to go to remove all doubt.

 

[Nick Rose]

I did get a reply from Lyngso and it is Silica. Don’t know if this makes a difference but they said it is washed sand.

 

[pdxmonkeyboy]

Silica and silicates are not the same thing by they absolutely go hand in hand. There is a reason people use argonite sand in there reef tanks and not play sand.

From that internet thing...

Silicon dioxide (SiO2) sand and fused quartz are silicas. Silicate minerals constitute about 90 percent of the Earth's crust. Silicates are anions containing silicon and oxygen (for example, orthosilicate, SiO4-4), and several are usually slightly soluble in water, so silicate salts are commonly present in water.

Its important to remember that sand in the ocean is not pulverized rock, its parrot fish poop from eating corals