Practical Guide to Reducing Nutrient Salts with NoPox and Bio-Pellets Carbon Addition
Explains carbon dosing to maintain low nitrate and phosphate levels in coral tanks. Covers NoPox, bio-pellets, and vodka dosing—mechanisms, dosing rates, and precautions in beginner-friendly terms.
Key Takeaways
Explains carbon dosing to maintain low nitrate and phosphate levels in coral tanks. Covers NoPox, bio-pellets, and vodka dosing—mechanisms, dosing rates, and precautions in beginner-friendly terms.
What is Carbon Dosing?
Coral aquariums accumulate nitrate (NO₃) and phosphate (PO₄) as bioload metabolites and uneaten food decompose. Rising nutrient levels cause coral bleaching, growth inhibition, and algae blooms.
Carbon dosing adds small amounts of organic carbon sources (sugars, alcohols, etc.) to stimulate heterotrophic bacteria, which consume nitrate and phosphate while multiplying. These bacteria are then physically removed via protein skimmer.
Called "ULNS (Ultra Low Nutrient System)," this approach is widely adopted to maintain vibrant SPS (small polyp stony) corals.
Main Carbon Dosing Methods
NoPox (Two Little Fishies)
NoPox is a commercial liquid carbon source containing alcohol and nitrate-reduction promoters. Dosed 1-2 times daily in small amounts per included guidelines.
Pros: Easy to measure, beginner-friendly, high safety profile. Cons: Relatively expensive, requires daily manual dosing.
Bio Pellets
Bio pellets are biodegradable plastic (PHB—polyhydroxybutyrate) in fine granular form, placed in fluidized reactors.
Water flow keeps pellets suspended. Heterotrophic bacteria colonizing the surface continuously consume nutrients. Skimmers remove bacteria.
Pros: Low maintenance once set up, stable dosing. Cons: Dedicated reactor required, bacterial bloom possible during startup.
Vodka Dosing
Adding ethanol from vodka directly as carbon source. DIY approach, inexpensive and readily available.
Dosing guide: Start 0.1–0.5 ml/day per 100L tank, adjust 0.1ml increments every 1-2 weeks. Caution: Overdosing drops dissolved oxygen sharply, risking fish suffocation. Advanced users only.