Silica Sand May Fizz

[Shoestring Reefer]

I'm starting this thread because I read lots about the "fizz test" and people saying, "if it fizzes, it's calcium based and not silica or quartz based". It's a fine theory, but anyone who has mixed vinegar and baking soda will remember that calcium-based sand 'aint the only thing that fizzes. And I'm shure that we can all believe that silica play sand isn't 100% silica.

rant
SILICA SAND MAY FIZZ!!!! No, it's not the silica fizzing, but I added vinegar to silica sand and some of the other "stuff" in the sand fizzed. 2 tablespoons were able to fizz about 1 cup of vinegar. I added the vinegar bit by bit, stirred it until it stopped fizzing, waited a while for the slower-forming bubbles to stop, and then added more vinegar. It kept fizzing until I was out of vinegar (about 1 cup).

The silica-based sand DEFINATELY looked silica- or quartz-based: shiny, jagged pieces. When I started, there was lots of dusty stuff that had a non-shiny appearance, and after the fizz test I couldn't see any of that stuff--all of teh remaining solids looked shiny. Basically, I fizzed away lots of imputities in the silica sand.

In short, I recommend the sand type be verified by (a) reading the label, (b) doing a visual inspection, or (c) completely dissolving a sample--this seems to take a lot of vinegar, so use a small amount of sand. Simply seeing if it fizzes is not adequate.
/rant

[Travis L. Stevens]

I don't believe its a matter of it "just fizzing" but foaming copious amounts. I haven't done the test for my self, but since calcium carbonate reacts with the vinegar and "SW aquarium sand" is comprised mainly of this, it will fizz like crazy. As for silica based sands, Im sure it will have something in there that will react to vinegar and make it fizz, but not nearly the amount like Southdown for example. But yes, a confimration on the actual ingredients are a must. Even if you have to snail mail the manufacturer for a list of the minerals that are in the sand.