The invention provides methods and compositions for inhibiting the accumulation of DSP scale in the liquor circuit of Bayer process equipment. The method includes adding one or more GPS-surfactant based small molecules to the liquor fluid circuit. These scale inhibitors reduce DSP scale formation and thereby increase fluid throughput, increase the amount of time Bayer process equipment can be operational and reduce the need for expensive and dangerous acid washes of Bayer process equipment. As a result, the invention provides a significant reduction in the total cost of operating a Bayer process.