The present invention is a system to continuously monitor, in real-time, the small molecules being dialyzed during hemodialysis treatment using Raman spectroscopy and press control algorithms. By monitoring the treatment, the amount of water needed per dialysis treatment is drastically reduced by optimizing analyte saturation and removal of wastes. This will significantly conserve water and reduce the cost of dialysis treatments, possibly reducing the amount of time necessary for dialysis treatment, improving quality of life for patients during and after treatment, and reducing the costs of building new treatment centers as well as operating costs.