Monday evening CMAS Gas Blender & Service Technician course in Aquarius at Østerbro. First out of two parts, this time was about laws and regulations, cleaning methods in theory and practise, physics, and blending methods in theory. Next monday we do practical blending and exams and certification. After that I should be able and allowed to mix own blends for myself and others. Aquarius has a very nice and brand new Bauer compressor, continuous fill blending system, booster pump, and (relatively) cheap oxygen and helium.