Resurfacing a concrete pool typically involves cleaning and preparing the surface, repairing any cracks or damage, and then applying a new layer of concrete. Depending on the condition of your pool, additional steps such as acid washing or patching may also be necessary. If your concrete pool needs to be resurfaced, it is important to contact a professional pool builder who has experience in this type of work. They will be able to assess the condition of the pool and recommend the best course of action, which may include patching, acid washing, or applying a new layer of concrete. The cost of resurfacing will depend on the size of the pool and the extent of the work that needs to be done.