good test but nobody needs this for a swimming pool
phosphates in pools can actually just be ignored by almost everyone, they are another pool store "free test" scam measurement designed to sell products, but I am a nerd and I was curious. I wanted to see for myself. over 6000 ppb and pool is crystal clear. that is because I test myself (using other Taylor products) and know exactly what my water needs. CYA, liquid chlorine and muriatic acid are all I EVER put in the water. I could afford the test out of curiosity because I save so much money not buying magic potions from the pool store.