Refugium has a side benefit that value adds to your system.
it soaks up CO2 and increases the pH of your system. Is a good natural pH buffer AND promotes calcification. You can grow macroalgae for tangs, offers a refuge for copepods/amphipods.
Even with high levels of predators, a refuge for the preys allow them to not go extinct in your system and multiply.
refugium is a proven nutrient export method with many side benefits.
bacteria media is an anecdotal nutrient export at best without the side benefits.