Aqua Medic Denigran 4 × 50 g

Aqua Medic Denigran is a biological filter media for aquariums designed to reduce nitrates naturally and help control algae growth in both freshwater and marine systems.

Key specs

• Type: Biological nitrate-reducing filter media
• Packaging: 4 mesh bags × 50 g (total 200 g)
• Aquarium size coverage: ~100–200 liters per pack
• Use: Freshwater & saltwater aquariums
• Lifetime: up to ~12 months (depending on bio-load)
• Form: Plastic granules in mesh bags (ready to use)

What it does

• Promotes growth of denitrifying bacteria inside the media
• Converts nitrates into harmless nitrogen gas
• Helps reduce algae outbreaks by removing nutrients
• Works without chemicals or additives
• Acts as a long-term biological nitrate filter

How it works

• Water flows slowly through the mesh bags
• Inside, low-oxygen zones form where bacteria develop
• These bacteria consume nitrate as their energy source
• Nitrogen gas is released harmlessly into the water

Important notes

• Can take 3–6 weeks to fully activate (bacterial colonization phase)
• Slight water cloudiness may occur at the beginning (normal bacterial bloom)
• Should not replace regular water changes
• Needs proper placement with good but not too strong flow
• Do not rinse with tap water once colonized

Who it’s for

• Aquarium owners struggling with high nitrate levels
• Reef and freshwater hobbyists wanting natural algae control
• Medium tanks needing long-term biological filtration support

Not ideal for

• Tanks without existing biological filtration (needs mature system)
• Users wanting instant results (it works gradually)
• Poorly maintained tanks with extreme waste load