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.
Brown algae is the largest, most complex type of algae. This type of marine algae is brown, olive or yellowish-brown in color. Brown algae contains chlorophyll a and c and a pigment called fucoxanthin, which gives it its color. Fucoxanthin is not found in other algae or plants. Unlike red and green algae, brown algae are in the Kingdom Chromista. Brown algae are often rooted to a stationary structure such as a rock, shell or dock by a structure called a holdfast, although species in the genus Sargassum are free-floating.