Can phosphates alone cause cloudy pool water? If so, under what circumstances does that occur? Not counting the use of phosphate removers.
"Phosphates are excellent plant fertilisers. They do no detectable harm in humans (in fact, phosphorus is an essential element for all known life). However, many phosphate salts are insoluble and form very fine precipitates. If the metals that combine with the phosphate are calcium or magnesium, the precipitate will be white, and if it is finely dispersed, the water will take on a cloudy appearance.
Filtration won't work on this type of cloudiness, because the solid has very fine particles. Your best bet would be to either drain, clean and refill the pool, or to add a coagulant that will precipitate the phosphate completely, and then remove the settled solid. Ask at a specialist store what would be the best option."
I found the above quote in answer to a cloudy pool question on "yahoo answers" The answer came from someone claiming to be a doctoral student in analytical chemistry.
Can anyone verify this or refute it?