Eco-Complete contains NO fertilizer. It is high CEC, so it can hang onto fertilizer, but you absolutely definitely need to use fertilizer with it - even root tabs. It is completely inert on its own. Even the packaging tells you that.
Here.. howbout I give you some quotes from the manufacturers & Sellers..
Why does Eco-Complete™ planted aquarium substrate outperform other products? For the same reason that Hawaii, Bali and Costa Rica are famous for lush, exuberant plant growth. The secret lies in rich basaltic volcanic soil which contains iron, calcium, magnesium, potassium, sulfur plus over 25 other elements to nourish your aquatic plants.
Eco-Complete™ Planted Aquarium Substrate is mineralogically and biologically complete
, giving you luxuriant aquatic plant growth without nuisance algae! Iron rich Eco‑Complete™ eliminates the need for laterite.
No artificial dyes, paints, or chemical coatings. Eco-Complete™ has highly porous spherical grains for optimum diffusion performance and contains live Heterotrophic bacteria to rapidly convert fish waste into natural food for your aquatic plants. It establishes a natural biological balance which makes cycling a new aquarium faster and safer.
and this one:
Eco-Complete Planted Aquarium Substrate contains more than 25 minerals
to nourish aquatic plants. Packed in Liquid Amazon buffered "Black Water" solution, Eco-Complete offers immediate organic water conditioning - no rinsing required. Choose coarse- or fine-grade (black only) substrate to suit your exact needs. Eco-Complete includes live, Heterotrophic bacteria to convert fish waste into natural food for your plants. Both original Eco-Complete Black and Eco-Complete Red are iron rich and eliminate the need for laterite supplementation.
Sounds like it contains fertilizers to me? CEC has to do with the cations relating to PH value of a soil.. it's talking about the fact that it's able to hang onto the nutrients that it has.. and then some. Eco-complete is porous so it's able to not only retain it's nutrients (not losing the ones it already has) and accumulate new.. as well as host lots of bacteria. The definition of fertlizer is a natural or chemical substance added to a substrate to increase fertility. Natural/chemical substances are for example: iron, calcium, magnesium, potassium, sulfur.