What do you mean my cyanuric acid levels are too high and you have to drain the pool? Aren’t you supposed to prevent that? What does it do?
High cyanuric acid levels would hinder the efficacy (effectiveness) of the chlorine to act as a disinfectant. Higher levels of cyanuric acid will bind with the chlorine, making it slower acting to kill bacteria and micro-organisms, and prevent algae. Higher levels will also increase cloudiness in the pool water. At this point, it would be recommended that a portion of the pool water be replaced with fresh water, as there are no other means of reducing the cyanuric acid in pool water.
Any pool that utilizes powered, tablet, or stick forms of stabilized chlorine will be adding cyanuric acid, as most of the chlorine sold today contains cyanuric acid. Continual use of these products without regular water exchange will increase the cyanuric acid to a high level.