Play sand or not?

[Tiny]

There is a LFS owner in my area that swear's he uses regular play sand in all his tanks, home and store, reef or fish with no problem what so ever. He has a shelf full of live sand and such in the store. I questioned him about the contents of the play sand, but he lives by it. He is not speaking of SouthDown or any in that line either. What do you think?

[webdr]

are you thinking of using it cause its cheaper?

[MaryHM]

The problem with other sands is that they contain silica. Many people feel this can lead to significant diatom algae problems. Others think there's no proof that the silica is able to dissolve into the water and cause problems. I use southdown sand in all of my systems with no problems. Of course, I generally err on the side of caution!

[Tiny]

I don't plan to use or buy any kind. We were just talking in the store one day and he just stated his experience. Just wanted to see what others thought, even tho some things will work without all the expense. I threw out my protein skimmer a year ago and my tank has done better than ever. Probably several other things I don't do anymore that had to be done in order to keep a nice reef tank.

[tdwyatt]

Silica sand can support the life sound in most tropical benthos, but ideally you wpould want aragonite or calcite sands (two different morphic forms of CaCO3 sand), as there are some species that depend on the sand being calcium-based (bacteria and some other microfauna). This is not to say that the quartz-feldspar-silicate based sandbed can't be done, but half the reason for using calcium as a substrate has to do with its sequestering of phosphates in additiion to supporting the biotopically correct speciations of bacteria, microfauna and flora, meso, etc.

Recently read an article comparing organosilicates as sources for diatom blooms vs terrestrial (river-sourced from granite gneiss, feldspars, etc) sources, evidently there is a difference between the two, especially in view of the extremely low solubility of silicon dioxide directly from sand, glass, etc. I will try to find the article in the stax, those of you with access to the journal Marine Biology, you may be able to look through the index for this article, although I don't remember the date (late 90's or early 00's for sure)

Good test for the playsand to determine composition: pour about 4 oz of white vinegar into a teaspoon of the sample sand in a quart jar and agitate, if it is aragonite/calcite, it will dissolve.

hth

[Ms. K]

I use play sand in my 20L salt marsh, and I've never had the slightest problem with algae and I have fairly heavy lighting on a small amount of water (part reef/part beach). The water is always crystal clear and the critters are happy as can be. There is a substantial colony of worms living in the sand and some feather dusters have also setup home there. This is the only tank I have the sand in, but it's doing quite wonderfully!

[Tiny]

Ms.K, would that be Southdown play sand or a regular Home Depot or Lowes, etc.?
Thanks.

[beach bum]

I never found a silica based playsand that I liked the look of, too dark and dirty looking imo.