Best Selling Products
CO2 Regulator PRO Extension – Dual Manifold Block Add-On
$26.99
Upgrade your CO2 Regulator with this manifold block extension, allowing you to run a second bubble counter and needle valve from a single regulator. Perfect for aquarists with multiple planted...
CO2 Splitter – 4-Way Needle Valve with FREE Extension Rod
$32.99
Easily distribute CO2 from one cylinder to up to four aquariums using the Castle Dawn Aquatics 4‑Way CO2 Splitter. Made from durable stainless steel and aluminium alloy, each needle valve...
Glass CO2 Drop Checker - Hang On Style
$12.57
Keep your planted tank thriving with the Castle Dawn Aquatics hang on Drop Checker. This elegant glass tool helps monitor dissolved CO2 levels in your aquarium, changing colour based on...
Castle Dawn Aquatics CO2 Glass U-Tube 15 mm
$6.75
The Castle Dawn Aquatics Glass CO2 U-Tube 15 mm is a simple yet elegant solution for routing airline or CO2 tubing over the rim of your aquarium. Designed for use with...
Castle Dawn Aquatics Glass CO2 Bubble Counter - 17 mm
$11.99
The Castle Dawn Aquatics Glass CO2 Bubble Counter is an elegant and easy-to-use tool for monitoring the rate of CO2 injection in your planted aquarium. By minimising the visual footprint...
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...