Reef Substrate

[SankTank]

i have 40lb bag of Aragonite here at my house from CaribSea that a buddy gave to me. Here are the elements:
Calcium 381,000 ppm
Carbonate Buffer 590,000 ppm
Strontium 7,390 ppm
Magnesium 1,050 ppm
Molybdenum 56 ppm
Potassium 56 ppm

Oolitic aragonite would be best

But you would need a sand bed of about 4-6 inches deep minimum to produce a stagnant environment

Is there a difference between this and oolitic aragonite? Also, what size sand bed would you recommend for a 4ft long reef dominated tank?

[SankTank]

Here is a good answer I found... Still not positive whether this is different from what I have.

What is Aragonite Sand? Aragonite mineral sand is formed as tropical waters warm and heat drives out dissolved carbon dioxide gas. With depleted CO2 levels, the ocean’s buffering system tries to maintain the equilibrium by breaking down bicarbonate ions thus producing more CO2 and carbonate ions. The carbonate ions combine with calcium in solution to form calcium carbonate which crystallizes into tiny spherical or ellipsoidal particles called oolites (egg stones) about the size of a pin head. These fall to the bottom and make thick deposits of beautiful organic sand.

[SankTank]

im thinkin a 4" sandbed in a refugium with aragonite, live rock, and chaeto w/ a 15w 14000k bulb. 2" sandbed in the display tank with aragonite w/ a high wattage t5 setup. my bud gave me an idea of turning my 55gal tank into a sump/refugium(would 55g's be too large for that?) and starting either a 90gal or 120gal. my dad just built a house so im gonna have him help me build a stand/canopy. havent picked out a 120g but it would be 72" which would leave plenty of room for the sump. theres some DIY stand videos on youtube, any advise on makin one? ill make sure to leave some room for storage and lights, need anything else in it? still doing research cause my finances arent ready to start my project.