So, water freely passes through the Seachem Renew and dissolved organics are retained. That being the case, would that mean that nitrifying and other bacteria can't get to work on these tasty morsels? If they can, then the organic waste would be broken down inside the filter and that would seem to be counterproductive, wouldn't it? Or maybe not.
I think I may have answered my own question. Seachem has this to say:
"Renew™ will remove organics and particulates in the sub-micron range; it will also help control ammonia, nitrates, and phosphates".
I think what Seachem are saying here is that ammonia, nitrates and phosphates are not produced inside the filter as a result of adding Renew.
As Monty Python used to say - my bwain hurts! (Spelling error intentional)