Keep in mind too, that all sand isn't equal. Coarse sand like pool filter sand is great. Fine, powdery sand like playground sand can compact over time smothering roots and creating pockets of anaerobic bacteria. A good friend of mine used playground sand at first with good results. A year later, his plants started dying and he decided to switch substrate. We found gobs of black slimy, stinky root material under there. Having MTS to sift through the substrate may have prevented this, but long term problems can arise if it's too fine.
92% of all statistics are made up on the spot.