when refugiums were the new craze, many articles suggested keeping some kind of macro algae in the refugium and keeping it under 24 hr lighting. The idea was the 24 hr photosynthesis would also keep your CO2 levels constantly in depletion to avoid pH daily cycles... including continuous phosphate uptake from the water around the clock. The macro algae also provides habitat & food for critters like isopods and amphipods etc.
the real reason I am advocating the lighting is... I shamelessly have a 36 inch double florescent light strip for sale in my For Sale thread. See link in my sig...
oops, just noticed you're in BC. I'm no where near you... but the thought on the lighted refugium is yours to keep