Individuals with normal color vision will see a number, while those with a deficiency do not see it. On some plates, a person with normal color vision may see one number, while a person with a deficiency sees a different number.
Your phosphate level should be at or below 100 parts per billion (ppb). If your water chemistry and phosphate levels seem to be in check, one potential cause of the cloudiness in your pool could be dead algae. Phosphates are the food supply for algae, thus high phosphate levels promote algae growth.
Inorganic compounds containing phosphorous. Used in fertilizers (as plant nutrient) and in detergents (as 'builders' or water softeners), phosphates are a major source of water pollution. There presence in lakes and ponds encourages explosive algae growth which depletes water-dissolved oxygen, resulting in elimination of other forms of aquatic life.