thanks everyone, i'm going to give it a shot and see how the plants take.
I don't have any real data like PAR to back up my claims, but I put one of those over my Evolve 4 instead of the stock LED light and my plants were growing pretty slowly. I went back to the stock light and there has been an explosion of growth in the last couple weeks! Nothing else has changed, same fert routine, etc.
You might want to stick with the stock fixture, it might be better than you would think.
ductape, what kind of plants are you growing? i'm not dosing anything in this tank except a single root tab.