Filtration

Refugium

Refugium buyer guide. Macroalgae-housing chamber that exports nutrients while housing pod cultures.

Refugium TL;DR

Price range: $100-$500.

Macroalgae-housing chamber that exports nutrients while housing pod cultures.

How refugiums work

Macroalgae-housing chamber that exports nutrients while housing pod cultures. Mechanical filtration captures particulates, biological filtration hosts nitrifying bacteria, and chemical filtration uses media (carbon, GFO, resins) to remove dissolved compounds.

Sizing for your tank

Rule of thumb: pick a filter rated for 4-6x your tank volume in gallons-per-hour turnover. Oversizing is safer than undersizing - cleaner water, more nitrifying surface area, more headroom for stocking growth.

Setup and maintenance

Rinse mechanical media in old tank water (NEVER tap water - chlorine kills bio-bacteria) every 2-4 weeks. Replace chemical media (carbon) monthly. Bio-media is permanent - never replace unless physically degraded.

Common refugium mistakes

Replacing all media at once - destroys the bio-filter. Rinsing in tap water - same result. Skipping pre-filter sponges - shortens main media life. Buying undersized for the tank - leads to ammonia spikes.

Cost expectations

Refugium runs $100-$500 new. Used units in working condition: 40-60% off. Replacement media adds $30-$150 per year.

Refugium FAQ

Is a refugium good for a beginner?

Yes - sized appropriately, all major filter types work for beginners.

How long does a refugium last?

5-15 years with normal use; impellers and seals are wear items.