silica sand

[jchump5415]

Hey Randy,
I recently put a post on ask Dr. Ron about my sand. When I bought it they claimed it was all natural. Now a local fish shop owner tells me that the sand is silica sand. The guy that sells the sand claims that it is reef safe. How can I tell if it is silica sand? The bag just says marine sand. Dr. Ron says the silica sand is ok but I would like to know if it is or not. Thanks

[Randy Holmes-Farley]

Jen:

<< How can I tell if it is silica sand? >>

Often by color (it is often more golden than CaCO3) but certainly by dissolution in acid (vinegar or muriatic). If it dissolves, it isn't silica sand.


<< Dr. Ron says the silica sand is ok but I would like to know if it is or not. >>

There are many people that have sand beds made of silica sand and they seem to be fine. Silica sand from Home Depot is a source of soluble silicate (I've measured it myself), but that doesn't mean it is always (or ever) a problem (the potential problem being diatom growth). FWIW, I add soluble silicate as a supplement to my tank.

Consequently, my opinion is that I prefer CaCO3 sand beds for a variety of reasons, but if you can't get CaCO3 sand, or already have silica sand and don't want to buy more sand, that it will very likely be just fine.

[jchump5415]

Thanks Randy! I put some of the sand in vinagar and it did not dissolve so I assume it is silica sand. I bought the bags of sand from a LFS so hopefully it is not soluble silicate. I surely am not going to be trashing all my 250 pound of sand that is in the tank. Thanks alot Randy!:fish1: