CO₂

If you want to take your planted aquarium to the next level, a CO₂ system is the way to go. By injecting carbon dioxide into the water at a controlled rate, you give your plants the boost they need to grow faster, healthier, and more vibrant. While not every setup requires it, many demanding plant species won’t reach their full potential without added CO₂. That said, a CO₂ system can be a bit tricky to set up and is usually recommended for more experienced aquarists. An all-in-one kit can make things easier, but you’ll still need to factor in regular CO₂ refills to keep it running. Before you invest, check whether your plants actually need it—some will thrive with just good lighting and nutrients, while others depend on CO₂ to really flourish. For step-by-step help, see our full guide on setting up CO₂ in your aquarium.