If your pool is green you have a green algae problem now. You really need to do something, and now. You have this problem because of a lack of chlorine. Yes, add extra chlorine, but you can’t add enough chlorine to kill all the algae. You will need an algaecide and heavy chlorine boost as well. Green water is always because of a chemical imbalance. Rarely–very rarely–is it due to some type of equipment failure.
There are a variety of effective algaecides available for your fight against green algae. There is an ammonia algaecide, but that is best used as a preventive measure or for yellow algae. Silver algaecide is effective but believe me, it’s too expensive to consider. What you need is a chelated copper algaecide.
Copper algaecide is your best solution because it’s relatively inexpensive and doesn’t foam. Foaming will be a problem if you use an ammonia algaecide for this problem. When you use a copper algaecide it won’t foam, but it could stain your pool as you use it.
Use these two simple tricks and you will be astonished at how well you can get rid of the green algae in your pool. First pour water into a two gallon bucket. Then add one quart of copper algaecide for every 20,000 gallons in your pool. Most play pools are between fifteen and twenty thousand gallons. Most diving back-yard diving pools are between eighteen and twenty-five thousand gallons.
Take a couple of seconds to mix it into the water then walk around your pool carefully pouring it in. I know it sounds crazy, diluting it before adding it into a big body of water, but by doing it this way you won’t stain your pool… but don’t splash it on the deck or you still could stain that.
Next you will almost always need a heavy chlorine boost or shock, whether granular or liquid. I prefer granular because it has more staying power and a longer boost. I have a word of warning when you buy shock: the larger the package and cheaper the price, the less effective it will be. Take control of the green algae in your pool. Kill it the first time, or you will be working on it all summer.