Eco Complete is one of my fav substrates to use, it has a great look and lasts for quite some time to provide nutrients. Most people I've spoken to do not need extra root supplements like laterite in their eco complete - dosing with a PMDD (Poor Man's Dosing Drops) is generally sufficient.
What Kryten says is pretty much the truth though, good lighting is very important. But you have to make certain that you're adding in CO2 and Macro/Micro nutrients atop that to ensure you've got a well fed system.
Do that, and you're solid gold
