Frogboy

Chemically speaking, it is inert. None of the minerals contained in it are soluble. The plants have to break the substrate down enzymatically, as all plants do with all soils. For all practical purposes, it is crushed clay. Remember, there is a big difference between nutrient content and mineral content. I bet if you did a full analysis of Akadama you would find it has a high mineral content as well. That is what makes clay, well, clay. Of the three major fertilizers, only Potassium is present in Flourite. It is entirely devoid of Nitrogen or Phosphorus, so the biggest effect you might see is increased flowering. Maybe that's why my container plants always do so well.

As far as price goes, the cheapest I have seen Akadama (before shipping) is $20 for 20 lbs. Granted, I haven't searched exhaustively. You can find Flourite for around $12 for 15 lbs. I can't speak for the volume, but I believe that Akadama is slightly more dense than Flourite.

At any rate, it is simply another option.