Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of the detection of a low fluence blue light stimulus by the blue low-fluence system. Blue light is electromagnetic radiation with a wavelength of between 440 and 500nm. The blue low-fluence system responds to blue light at or below 0.1 micromols/m2. In certain species excitation of the blue low fluence system induces the transcription of a number of nuclear and plastid coded genes.