Advances in material science, optics, and electronics allow the creation of simple and low-cost measuring devices for various applications. In the present work, an optical multisensor system was designed using Cu(I) molecular emitters as a light source. The major advantage of this measuring platform is the ability to adjust the source wavelength for a particular analytical task. Here the possibility to measure fluoride and phosphate content in natural and tap waters using the optical setup with a UV flashlight as an excitation source for Cu(I) complexes has been demonstrated. The root mean-square prediction error (RMSEP) value for analyzed water samples attained with partial least-squares (PLS) regression method was 0.07 mg/L for both fluoride (0–0.4 mg/L concentration range) and phosphate (0–0.96 mg/L). These values are comparable with those for standard analytical techniques. This proof of concept study confirms the possibility of constructing adjustable optical multisensor systems based on Cu(I) emitters for real-life applications.