Really interesting and long lived thread, I used Akadama back in 2003-5 when keeping FW, since moved to Marine and now back to FW. I used it as both a substrate and filter media in a fx5. I can assure those who doubt the breakdown quality of a decent brand that it will not breakdown if you get a quality hard brand. As a filter media its excellent, given it was in an FX5.. theres not much more of a test given the water flow thru it.
My new build planted tank will use a base layer of Hard Line Akadama Bonsai Soil with a seachem flourite topper. Having used Akadama many yrs ago, I can vouch for its fantastic qualities, Seachem is without doubt a star brand in the marine world, lets see how it fairs in FW 🙂