Filter Media
Clear water. Clean chemistry.
Nereus Activated Carbon is a premium, aquarium-grade carbon chosen for polishing reef systems: removing dissolved organics, yellowing compounds and residual medications after treatment — without the harsh phosphate leach that cheap carbons are known for.
Crystal-clear water is not only aesthetic. Lower dissolved organic carbon means less fuel for bacterial blooms and a cleaner reading of your reef’s true colour under quality lighting.
Why reefers choose it
- High adsorption of DOC and discoloration
- Low-phosphate formulation suitable for reef use
- Reactor or filter-sock friendly granule size
- Fast clarity recovery after water changes or medication courses
- Consistent quality for international shipping and long-term storage
How to use
- Rinse in RODI until the water runs clear to remove dust.
- Place in a reactor, media bag or canister where flow contacts the entire bed. A light tumble in a reactor is ideal; a packed sock still works if flow is strong.
- Start with a modest charge (many reefers begin around 1 tablespoon per 40–50 L / 10–13 US gal) and increase only if water still yellows.
- Replace on a schedule — typically every 2–4 weeks in a busy reef, sooner after medication or a heavy organics event. Exhausted carbon stops protecting clarity and can become a nitrate sink if left forever.
- Remove before some treatments that rely on active medication remaining in the water, then reinstall once the course is finished and directed by the product instructions.
Best practice
- Keep carbon and GFO in separate stages when possible.
- Pair with good mechanical filtration and skimming for longer media life.
- Store sealed away from humidity and chemical fumes.
Activated carbon is the quiet polish behind a “glass-like” reef — simple, reliable and part of a high-quality filtration stack.