Yes, ClearBlue works well on gunite and plaster pools and spas. There are a few things to keep in mind:
1) We suggest using a pre-filter when filling a plaster pool or spa with water to remove impurities from the source water. We recommend a high quality product like the metal trap filter from HydroPure.
2) New gunite pools require acid washing which lowers the pH. It is important to keep the pH in the proper range of 7.2 to 7.6 so that the chlorine residual is effective and to minimize the risk of staining the pool surfaces.
3) Set the ClearBlue controller according to the operating guide for your spa or pool size. Test the copper level with the copper test kit, and adjust the Ion Action level accordingly to keep the copper ions between 0.2ppm – 0.4ppm.