Freshwater Aquarium CO₂
Enhance aquatic plant growth and improve aquarium health with our premium range of freshwater CO₂ equipment at Charterhouse Aquatics. From complete CO₂ kits and precision regulators to diffusers, bubble counters, and high-quality cylinders, we offer everything you need to maintain a stable and efficient CO₂ system. Our trusted brands—including JBL, CO₂Art, Tropica, and Aqua Medic—make it easy to optimise photosynthesis, reduce algae, and promote vibrant, lush aquatic plants. Shop now to build your perfect CO₂ setup for a balanced and thriving planted tank.
Freshwater Aquarium CO₂ Explained
Complete Beginner's Guide
Have Questions About Freshwater Aquarium CO₂?
We have answers. Get quick help for common questions.
Why is CO₂ important in a freshwater aquarium?
CO₂ is essential for healthy plant growth in a freshwater planted aquarium. Aquatic plants use CO₂ during photosynthesis to convert light into energy, which promotes stronger growth, richer coloration, and improved oxygenation for fish. Without enough CO₂, plants can struggle to thrive, and algae often takes over as a result.
What components do I need to set up a CO₂ system?
A basic CO₂ system includes a CO₂ cylinder, a regulator with needle valve, a bubble counter, a diffuser or atomiser, and tubing to connect it all. Some setups also include solenoids for automated control or pH controllers for fine-tuned dosing. Many of these are available as complete kits, ideal for beginners looking to simplify setup.
When should I run my CO₂ system?
CO₂ should be added during the lighting period only, as plants only photosynthesise when exposed to light. Most hobbyists run their CO₂ system about 1 hour before the lights turn on and turn it off 1 hour before lights go off. This improves efficiency and reduces CO₂ waste overnight.
How often do I need to refill my CO₂ cylinder?
It depends on the size of your cylinder and how much CO₂ you’re dosing. A 2kg cylinder can typically last 2–3 months in a 100L tank with moderate dosing. Keeping a backup cylinder or regularly checking your gauge will help you avoid unexpected shutdowns.
Do I need a CO₂ system for my aquarium?
If you’re keeping a heavily planted tank or growing demanding plant species like carpeting plants or red stems, then yes—a CO₂ injection system is highly recommended. While low-tech aquariums can survive on ambient CO₂ and liquid carbon additives, a pressurised CO₂ system provides consistent, long-term benefits and unlocks the full potential of your planted setup.
How much CO₂ should I add to my aquarium?
The target CO₂ concentration for most planted tanks is around 30 parts per million (ppm). This can be monitored using a drop checker or pH/KH chart. You want enough CO₂ to fuel plant growth without stressing fish, so start low and gradually increase while observing your tank’s response.
Is CO₂ safe for fish and shrimp?
Yes, when properly regulated, CO₂ is completely safe for fish and shrimp. Problems only occur if the CO₂ concentration becomes too high, leading to oxygen deprivation. Using a reliable regulator and testing with a drop checker can ensure safe and stable levels.
Can I use liquid carbon instead of gas?
Liquid carbon products like Seachem Excel can provide a CO₂ alternative in low-tech tanks, but they’re not a true replacement for pressurised CO₂ in high-demand setups. They’re useful for algae control and low-light environments but won’t support rapid plant growth like injected CO₂.
Take your planted aquarium to the next level with high-performance CO₂ systems and accessories from Charterhouse Aquatics
Our freshwater CO₂ collection includes everything from complete kits to advanced regulators, precision diffusers, drop checkers, and accessories designed to ensure optimal carbon dioxide distribution and healthy aquatic plant growth. Whether you’re setting up your first planted tank or upgrading your existing system, we carry top brands like JBL, CO₂Art, Tropica, and Aqua Medic to help you maintain balance and unlock lush, vibrant aquascapes. Trust Charterhouse for all your CO₂ needs and build a tank that flourishes naturally.
