Chlorine levels, PH level and Total Alkalinity are tested and adjusted weekly. For salt generating systems, the salt level will be tested and added as needed. Calcium hardness and stabilizer will be tested as needed.Other factors such as rain, the use of pesticides or fertilizers, pollution, the use of suntan oils, spills of cleaners or other household products added to the pool accidently or intentionally can dramatically change these levels causing problems.In a plaster pool the application of the plaster affects the long term appearance and stability. Pool plaster will degrade over time, discolored areas, pitting and other problems are inevitable. The proper application of the plaster, brushing the plaster twice a day for the first two weeks after application, and the maintenance of the chemical levels of the water can mitigate these problems but not eliminate them. The average life span of pool plaster is 5 to 8 years.Colored plaster especially will change color over time. An uneven pattern of color, sometimes referred to as mottling will occur, usually the builder will warn the customer of this. By testing and adjusting the chemicals weekly, Apex Pools will be able to slow down the degradation of the plaster, but not eliminate it.Apex WILL NOT assume any responsibility for the condition of the pool surface or equipment. The water will be tested and adjusted to A.P.S.P. standards.