ok substrate test inprogress.

[powerreef]

Hey folks I know the delima to search for a sandbed that we all can afford. I have read the threads above and would have to worry a little bit about it. If this product has so much Mag. it in it will poisen your tank over time with the fact that it is Mag carbonate that would indicate that the carbonate Ion will dissapate the mag. more readily. Another thing is that this product is mined and sold with a completely different perpose in mind. I sure this product is more than likly to be cross-contaminated with whatever had been sitting next to it in the baggging facility or on the ground from where the dump truck left it, also what about metals from the collection process (crane scope, rusting dump truck, bulldoser). anyway just my thoughts.

Oh ya on the Mag. to obtain high levels of calcium in our tanks we add calcium carbonate (through either a reactor or additives) the carbonate ion causes the calcium ion to dissapate very quickly. What Mag does to help retain calcium in our tanks is that its ion coats the carbonate ion and thus slows the dissapation down so that the calcium can remain soluable in our water. Sometimes reef tanks just cant seem to get over the 300 ppm mark this is usually from a lack of Mag.

good luck
mike