Perfectly clear green water

[maxmax]

My water is perfectly clear but green. I've had it tested for algae but none present. Phosphorus levels were well over 1000 ppb but I've brought it down to 800 or so. It's less green but still green. Am I on the right track thinking the phosphorus is the culpret. (Of course a pool maintenance guy told me about the phosphorus)

[aylad]

I'll let some of the chemists chime in here, but usually when the water is clear, and green, it's a metal of some sort. Don't know what color phosphorus would produce, but I do know that copper creates green clear water. Have you had the water tested for metals? What is the source of your fill water? Do you use any copper containing chemicals (algaecides, dual action trichlor tabs, etc)?

[PoolDoc]

I'm pretty sure 1000 ppb => 1 ppm of phosphorous is not going to cause green water. If it did, Sprite and 7-Up, which contain many hundreds of ppm phosphorous (as phosphoric acid) would be green as a gourd!

Green is usually either iron or algae. Clear green is often soluble iron, which can occur under various conditions, including low pool pH.