JBL ProFlora CO2 Set Basic are modern, user-friendly CO2 systems with functional details and simple operation. As entry-level systems, these CO2 systems are ideally suited for beginners. The set includes all components to visibly promote the growth of aquarium plants by adding CO2. You have the choice between a set with disposable bottle (Set U), refillable bottle (Set M) or without CO2 bottle (Set V). All components, except the CO2 supply bottle, are identical in all three systems.Why a CO2 system is necessary in the aquarium:: Plants provide the aquarium with vital oxygen for your aquarium inhabitants, prevent algae growth, remove pollutants, provide hiding places and reduce pathogens. Plant fertiliser systems with CO2 cylinders supply the plants with the main nutrient CO2 through the water. The plants absorb this and convert it into sugar and oxygen in photosynthesis with the help of light.The CO2 systems of the JBL ProFlora Basic series are available in three versions as Set U, Set