Conventional aquarium hoses are made of PVC or silicone. An aquarium hose specially made for aquaristics is food-safe and contains no plasticisers or other substances that could harm the inhabitants of the aquarium. Please make sure that the inner and outer diameters of the hose and the hose spouts are compatible with each other. It is a good idea to select tinted, slightly transparent material for visible hoses so you can see blockages. However, light-impermeable material also has its advantages: without light, less algae builds up in the hose. For saltwater aquariums, you should ensure that the material is suitable for long-term contact with saltwater. For the CO2 system, please use special gas-compatible hoses.