Rhinox Nano Carbon Dioxide Co2 Diffuser Glass Reactor for Aquarium Tank Plants Spiral Improve the growth & health of your plants with sufficient Co2 supply Atomic pores on the ceramic disc breaks down Carbon dioxide into tiny streams of bubbles With high surface area per volume ratio, Co2 can easily dissolve Experiments show Co2 dissolve rate close to 100% - Suitable for tanks about 55 US gallons (200 liters) - Compatible for pressurized Co2 tanks, but not yeast bottles Size: 1 inch in diameter.