Question

should you use low or medium for a defuser

Answer 1

It depends on the specific brand and type of diffuser you are using. Some diffusers may have specific settings for low, medium, and high while others may have a dial or settings for various levels of output. It's best to refer to the instruction manual that came with your diffuser for guidance on the appropriate setting to use. In general, starting with a lower setting and adjusting as needed is a good approach.