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.
The appearance of brown algae in an aquarium is most often blamed on silicates in the tank water. Just like SPS corals that require calcium to grow, diatoms require silicates to grow. However, there are many other factors that cause brown algae and I believe the excess silicates story is way overplayed.