aqua_chem
Aquarium Advice Addict
what is your substrate? i know that you don't want to dose ferts or co2, but if you have nutrients in the substrate, then you grow low-medium maintenance plants without problem. also, it doesn't make sense to me that you would invest the money in a quality light but not substrate
if you already have eco complete, you can grow about i would say half of the plants out there. if you don't mind, you can always grow stem plants like ludwigia, although you will not get the redness that a lot of people want since ludwigia needs co2 for redness. wisteria, rotala indicas, anubias, ferns, moss, dwarf sag, riccia, vals, and etc are also good.
I think you are grossly overestimating the importance of substrate. I usually put it dead last on my list of importance.