HI83303 is a compact, multiparameter photometer for use in aquaculture applications. The meter is one of the most advanced photometers available with an innovative optical design that utilizes a reference detector and focusing lens to eliminate errors from changes in the light source and from imperfections in the glass cuvette. This meter has 20 different programmed methods measuring 12 key water quality parameters and also offers an absorbance measurement mode for performance verification and for users that would like to develop their own concentration versus absorbance curves. Aquaculture parameters include alkalinity, calcium, nitrite, and phosphate which are critical to maintaining a healthy system. It also contains parameters specific to either a marine or freshwater environment.