Myth or fact?
 

I was doing some reading lately *lol oh no* anyways, has anyone noticed that crushed coral substrate actually releases minerals and other good things back into the water over time or is this just a myth?

What a Calcium reactor does is dissolve aragonite for calcium and
carbonate but it also releases the other trace elements.

CC, DSB will also dissolve down to some amount in normal tank pH but at a slower rate. Assuming the source isn't contaminated, what's released is good.

what would be a sand containing high, good mineral content for this application?

Product based on a aragonite would be a good choice. There's a few different companies/quarries Caribsea being one. Basically don't go to the river with a shovel.

Take a read here as well. Lots of topics, lots of info.

I personally would not consider anything from my substrate in any chemical equations for my water quality. I do not believe any substantial amount of calcium is disolved at aquarium pH rates. I will agree on a good quality subtrate, if you plan to use any, to avoid any contamination.

so how is it that contaminations make way into your water through substrate and calcium can't?

Calcium dissolves (in the case of a calcium reactor) when the PH levels inside the reactor are brought down to a certain point through the use of CO2. This is how I understand it (please someone correct me if I'm wrong!).

The PH inside your aquarium needs to be much different than that inside a reactor, in order for your organisms to survive.

The only theory that makes any sense is that there is a lower pH in the sand bed when it is deep enough to create an anoxic zone and CO2 builds up. I've never seen any proof of this but if it were going to work this is what would have to happen.

Not CO2 but H2S is produced in DSB's. I have wondered if a Calcium reactor also releases Mg in sufficent concentration. Does anybody know here?

Leaching from the surface of the substrate.