I'm not sure you could say Flourite and Eco-Complete are "inert", they both contain iron and micro-nutrients. something that is "inert" would have literally nothing, like basic gravel or sand.
Eco-Complete also includes live bacteria that they claim breaks down aquarium waste.
both are made specifically for planted aquaria, and IME they have proven to be very effective.
here is a link to something I haven't used, but you might be interested in:
http://www.aquariumplants.com/Freshwater_Aquarium_Plant_Substrate_p/ss.htm
if I hadn't already put Eco Complete in my 90G a few years back, I would have bought this stuff . . .
Eco-Complete also includes live bacteria that they claim breaks down aquarium waste.
both are made specifically for planted aquaria, and IME they have proven to be very effective.
here is a link to something I haven't used, but you might be interested in:
http://www.aquariumplants.com/Freshwater_Aquarium_Plant_Substrate_p/ss.htm
if I hadn't already put Eco Complete in my 90G a few years back, I would have bought this stuff . . .