There's a reason why people have to add nitrates to their water with things like stump remover - plants absorb them. Same for phosphates. Not only do I know this from reading and studying but from experience - all of my heavily planted tanks have readings of 0 for nitrates until I do water changes with my slightly nitrate-ified Philadelphia tap water, and within a few days all of the nitrates are gone.
There are many very experienced plant keepers who post on this amd other forums who maintain highl;y advanced planted tanks with very little and sometimes no water changes at all. Now while I am not anywhere near that level of attainment, I would be hard pressed to say something in disagreement with these people. And the fact that they say they have to add nitrates to their tanks to keep up with their plants demand for them kind of shows that the plants just might...just might be consuming nitrate.
In addition to this, EasyBalance has absolutely nothing to do with the actions of plant matter. Its claim is that it contains the bacteria which eats nitrate. Therefore the assertion that plants and EasyBalance don't or do work for the same reason is beyond my understanding.
EasyBalance is liquid snake oil crap from tetra. Plants are living organisms which consume nutrients. Entirely different entities. :read: