Photomicrographs of Substrates!

[Anonymous]

hi.
I would like to read about the dissolving of aragonite sand. My personal bias is that there is no doubt that aragonite dissolves, and pH of some sand bed can be low. But rather or not the dissolution of aragonite add any calcium to the tank to any significant amount is not obvious to me. Can the sand bed settled over the year instead of the aragonite dissolved? How much of exchange are there between the anoxic and the upper region? Can some critter chew up the sand into finer particles, and the powerhead just blow it to be settled in the sump? Did anyone do any experiment on this?

 

[simonh]

It would be good to have something like an ICP analysis done on the Aragamax product to see exactly what levels of metals maybe added to the aquarium if it does dissolve in the DSB.

 

[Anonymous]

hi.
I thought an ICP analysis was done already, and something like Ca, Mg, Sr accounts for 99% of all the metals ??

People use CaribSea and other substrates on CaRxtor for years without any problem.

 

[MattM]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by simonh:
<strong>It would be good to have something like an ICP analysis done on the Aragamax product to see exactly what levels of metals maybe added to the aquarium if it does dissolve in the DSB.</strong><hr></blockquote>

I don't know if an independent analysis has been done, but since the dissolved CaCO3 and other compunds that accrete to form oolitic sand grains are primarily from biological processes (i.e., coral skeletons), I would not expect it to contain materials inimical to corals.

 

[Anonymous]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by simonh:
<strong>It would be good to have something like an ICP analysis done on the Aragamax product to see exactly what levels of metals maybe added to the aquarium if it does dissolve in the DSB.</strong><hr></blockquote>

Sounds like a volunteer! You can paypal $300 USD to [email protected] and we'll get it done.

Seriously I don't think it's that big of a deal as these substrates have been used for years, I'd be more concerned about contaminants the quikrete product.

 

[liquid]

In a DSB, you could very well see aragonite dissolve -- IF the sandbed is deep enough and the anoxic conditions deep in the sandbed are low enough. As you dive deeper and deeper into the sandbed, anoxic conditions can drive the pH down below pH 7 where aragonite will begin to dissolve.

Shane