Aquarium CO2 Diffusers
Discover Our Range of CO2 Diffusers for Planted Aquariums
Achieve lush, vibrant aquatic plant growth with our expertly selected CO2 diffusers. Whether you keep a nano tank or a high-tech aquascape, our collection includes acrylic, glass, ceramic, and pollen-style CO2 diffusers designed to efficiently dissolve carbon dioxide for maximum plant uptake.
From sleek low-profile models to high-capacity options for larger tanks, each diffuser is built to deliver a fine mist of CO2—helping your aquatic plants thrive while keeping your setup clean and organised. Compatible with standard CO2 tubing, our range supports tanks from 10 to 250 litres.
Explore trusted options from Castle Dawn Aquatics and beyond, ideal for beginners and experienced aquascapers alike.
Acrylic CO2 Diffuser – Small (15 mm Ceramic Disc)
$14.99
The Castle Dawn Aquatics Acrylic CO2 Diffuser offers superior micro-bubble diffusion for planted aquariums. Designed with advanced micro-porous ceramic technology, it produces finer bubbles than traditional glass diffusers, allowing CO2...
Super CO2 Compact Internal Diffuser up to 45 Litres
$19.99 – $24.99
The Castle Dawn Aquatics Super Diffuser is a sleek, internal CO2 diffuser designed for smaller aquariums. It effortlessly connects to standard CO2 tubing and secures easily inside the tank, delivering...
External CO2 Atomiser with Locking Bolt Seal – Ultra-Fine Ceramic Diffuser
$27.99 – $32.99
The Castle Dawn Aquatics External CO2 Atomiser delivers a powerful and secure method of diffusing CO₂ into your aquarium. Designed for use with high-pressure CO₂ systems, this pro-grade atomiser uses...
Acrylic CO2 Diffuser – Medium (19 mm Ceramic Disc)
$17.99
The Castle Dawn Aquatics Acrylic CO2 Diffuser offers superior micro-bubble diffusion for planted aquariums. Designed with advanced micro-porous ceramic technology, it produces finer bubbles than traditional glass diffusers, allowing CO2...
Inline CO2 Diffuser with Nano Mist Membrane, Bubble Counter & Check Valve – 12/16mm Hose
$32.40
The Castle Dawn Aquatics Inline CO2 Diffuser offers a professional-grade solution for optimising CO₂ delivery in planted aquariums. Using nano mist membrane technology, it produces ultra-fine bubbles for maximum saturation,...
Small High-Density 'Druchtin' CO2 Diffuser – Below 250L/55gal
$19.99
The Castle Dawn Aquatics Large CO₂ Diffuser is designed for high-capacity planted tanks below 250L / 55 gallons. This precision in-tank diffuser uses advanced nano CO₂ mist membrane technology to...
Large High-Density 'Druchtin' CO2 Diffuser – Over 250L/55gal
$22.99
The Castle Dawn Aquatics Large CO2 Diffuser is designed for high-capacity planted tanks over 250L / 55 gallons. This precision in-tank diffuser uses advanced nano CO₂ mist membrane technology to...
Acrylic CO2 Diffuser – Nano (11 mm Ceramic Disc)
$12.99
The Castle Dawn Aquatics Acrylic CO2 Diffuser offers superior micro-bubble diffusion for planted aquariums. Designed with advanced micro-porous ceramic technology, it produces finer bubbles than traditional glass diffusers, allowing CO2...
Acrylic CO2 Diffuser – Large (25 mm Ceramic Disc)
$19.99
The Castle Dawn Aquatics Acrylic CO2 Diffuser offers superior micro-bubble diffusion for planted aquariums. Designed with advanced micro-porous ceramic technology, it produces finer bubbles than traditional glass diffusers, allowing CO2...
Curved Nano Large Acrylic 25cm CO2 Diffuser
$27.40
The Castle Dawn Aquatics Curved Special CO2 Diffuser (Large) is designed for aquascapers seeking a clean, hose-free layout in medium to large aquariums. Featuring a slim vertical profile, the diffuser...
Curved Nano Medium Acrylic 20cm CO2 Diffuser
$25.40
The Castle Dawn Aquatics Curved Special CO2 Diffuser (Medium) is designed for aquascapers seeking a clean, hose-free layout in medium to large aquariums. Featuring a slim vertical profile, the diffuser...
Curved Special CO2 14cm Nano Acrylic Diffuser
$16.99
The Castle Dawn Aquatics Curved Special CO2 Diffuser is designed for aquascapers who want maximum performance in a compact form. With a slim profile and side-mounted tubing connection, this acrylic...