I read this article and have a couple questions. I will also post the location just in case. Silica Sand/Aragonite Mix in a Reef? - 10/10/06 Hey. <<Hey>> I wanted to get your opinion on using play box sand for a reef tank. <<Is doable>> I have done a lot of reading on this and have gotten contradicting opinions, as with many issues in this hobby. <<Indeed>> I found sand called Kolorscape which is distributed by Oldcastle (same company that once distributed the famous but impossible to find Southdown). <<I've heard some about this sand before...supposedly aragonite based>> This sand is supposedly mined in a different area and is not purely aragonite. <<Easy enough to test>> From my understanding the sand passes the "vinegar test" but not all of the sand dissolves meaning it's mixed with at least some silica type sand. <<Hmm, maybe so...still...better than "all" silica. Not that using silica sand is necessarily bad, it just doesn't offer any buffer capacity/earth elements to the system>> It also clearly states on the bag that it may contain silica. <<Ah, I see...>> Is this really that big of a deal? <<Not in my opinion>> I read that silica sand is inert and won't release anything into the water. <<I don't think that is entirely true, but I think the concern for silica sand to foster huge diatom blooms or other maladies in our marine tanks is mostly overrated...and even less of an issue in the case of this "mixed" sand. I've used 100-percent silica sand in a couple marine systems over the years and can't attribute any deleterious effects to the use of the sand>> The source stated that it's only a rumor that won't die. <<As with so many of them>> In your opinion/experience have you found this to be true? <<As stated>> Should I spend the big bucks for aquarium sand or take a chance and save a bundle? <<Considering the Kolorscape does contain aragonite...I would use it>> I have read forums where people stated that they used Kolorscape and loved it, but the opinion was based on only a few months of use. Any thoughts? <<Perhaps you will let us know/write a piece on its performance>> By the way, I already have aragonite that will be used for the deep sand bed in the refugium so buffering won't be an issue. <<Likely wouldn't anyway...but very good>> I want to use the Kolorscape as a 1/2 inch deep sand in the display and am only concerned about the safety/silica issues. MarSubstSel3 I1. s it better to have argonite sand? 2. How do you test to see if it's argonite? 3. Is it true - if you put vinegar in the sand and it bubbles it is safe to use in your aquarium and you don't have to worry about anything else. (from another forum) 4. Does it matter if the sand you use contains silica? 5. Are maladies diseases? Do you think you need to get argonite so you won't get this? The only thing I know about sand is live, and not live and how to seed it. I'm pretty sure I either want white sand or Indo-Pacific Black (click on "arig-alive" to see the indo pacific black if you want) 6. I need advice and information about what to look out for when buying sand and if I choose to buy white sand what kinds are bad 7. or can I just buy any ol white sand and just seed it with my rock? Thanks.