Playsand and vinegar

[TriMax]

OK, it is me again.

I looked it up. The story is not a straight one.

Some would say, Add vinegar, if it bubbles that is bad.

Some would say, Add vinegar, if it bubbles that is good.

Most said silica is not bad.

So, now I do want to know what do you think?

Eddie

[steelhealr]

Vinegar = acetic acid
Shells or aragonite = Calcium carbonate (CaCO3)

Vinegar (acetic acid)+ shells or aragonite (CaCO3) = CO2 or bubbles

Calcium carbonate buffers SW in marine tanks and helps to maintain the alkaline pH that you want in your tank. SH

[Pico66]

I would have to say that silica is bad. Although there may be trace amount in most any sand, you really want CaCO3, and not silica sand. Diatoms and other algaes can utilize the silica, or the Silicon as the SiO2 breaks down in the water.

[RCS]

I've heard many of these arguments many times, with little to (more often) no proof cited at all.

Calcium-based sands, on the other hand: http://www.advancedaquarist.com/2005/2/short

There have been some discussions here on RC that would seem to strongly imply that Si can be a limiting component in a reef tank (though, aside from use by sponges and diatoms, it's not clearly understood what is actually using it!):

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=79001

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=78802

Heck, Randy Holmes-Farley ADDS silicate to his tank on a DAILY basis, having run tests that conclude the silicate available in his reef is used up every 4-5 days.

Having set up and run at least 5 marine tanks with regular old play sand, and having never had a diatom bloom of any sort aside from the regular breaking-in period (which I've had in every tank set up with tap water regardless of substrate), I can say I've never had a problem attributable to the sand used in my substrate.

I'm not saying there is not some small amount of silica put into the water, but from all appearances it's very minimal, used quickly and shouldn't pose any more problem than the silica and phosphorous leeched by aragonite sands.