Don't get scared The green water is the high chlorine combining with a ph of 7.6 to make the metals in the water "stain the water". The metal sequesterer will bind with the metals and keep it from coloring the water. Having a well will probably mean that you will have to keep metal sequesterer in your water at all times. It is not a problem. You can read over some of the posts in the stains and metals forum. Welcome to the forum and congrats on the new pool