That depends on the "Goal" of the "Fuge"...
"Fuge" being a generic term for a number of different types of supplemental chambers added to a tank system...
Sump= an additional chamber for increasing water volume and a place to put extraneous equipment out of the main tank (heaters, skimmers, pumps, etc...)
Refugium= a safe chamber or place free of "predators" for the propagation of micro flora and fauna .....(in this case a "pod" refugium could be a dark cryptic zone which would NOT "require" lighting)...if the "Goal" was to grow macros for feeding fish in a predator free environment lighting would be neccessary...
Algal Scrubber Filtration= Differs from fuge in that the main "Goal" is the forced propagation of Macros for the absorption and removal of malnutrients thru export or "harvesting" and would require significant lighting...(pod production ,if any, is a side benefit and not the main focus..)
Not all "Fuge's" are created equal nor are they able to do all things equally well...a "Goal" or purpose needs to be established and then the fuge/refugium/algal scrubber needs to be set up to meet those "requirements"...
Sizeing, Flow rates, lighting (amount and schedual), structure and inhabitants all play a significant role in setting up a successful "fuge"<<<generic term<<< to meet your "Goals"..
