A number of factors can lead to green water. The most common reasons are a lack of chlorine (or shocking) and a high metal content in your pool’s source water. A lack of chlorine, or shocking your pool, will initially make the water fuzzy and unclear and, eventually, green and swampy. Green water from lack of chlorine will most likely have a low-to-zero chlorine reading and look somewhat slimy. You may even see clumps of algae growing on the floor of your pool. See the next question for instructions on how to fix this problem.
Another reason for a green tint in your swimming pool or spa is caused by a high metal content in the source water. You can usually tell between the two by the visual aspects. High metal green water usually has a chlorine reading from normal to high and is clear to the bottom, but it is tinted green comparable to someone pouring food dye in the water. If you believe metals are the cause of your problem, we recommend adding one quart of metal remover per 10,000 gallons of pool water. You should start to see results within 12 hours. Most metal removers require you to clean your filter 24 – 48 hours after treatment. It is important to read the directions of any chemical you add to your pool before use. If you are still having problems, contact us.