wikipedia definition of a REFUGIUM:
A refugium is an appendage to a marine, brackish, or freshwater fish tank in which water flows in, baffles slow it down to allow a certain amount of stagnation, and flows back out into the tank. Sizes vary from as small as a shoe box to as large as an entire aquarium. Inside the semi-stagnant portion, various suppositories can be placed to allow biological filtration to take place. The items depend on the type of tank, but common items include crabs, snails, or other creatures that will break down solid waste, or certain algae or live plant species to reduce nitrate and phosphate levels.
To get the maximum biological filtration (through uptake of nutrients by macroalgae/mangroves), strong lighting can be used on the refugium. The refugium light cycle can be operated opposite to the main tank, in order to keep the total system pH more stable (due to the uptake of acid-forming CO2 by the refugium during its daylight hours).
So what i understand that since my macro is growing...obviously my macro is consuming something right? so how is it now working?