If your swimming pool is green and cloudy, it is not safe to swim in, but with the right treatment, you can make the pool safe again. In some cases, the pool may be so green and full of algae that you have no choice but to drain your pool and treat it with an acid wash to kill the algae and bacteria that infest the pool. However, if you can see for at least a foot down into your pool, then you can clean the pool in the following way.
If the ph balance in your pool is too high, then any attempt to clean your pool will be futile. Thus, before you do anything else to rid your pool of its cloudy green filth, you need to restore it to its proper ph balance. Use a test strip to determine how high the ph balance in your pool is, then turn your pool filter on, add diluted muriatic acid to your pool, then wait for a few hours. As you add the acid, make sure that you don't dump it into the pool all in one spot. Instead, poor a little at a time as you walk around the full circumference of your pool. Let the filter do the rest of the work of spreading the acid throughout your pool.
Your next step in cleaning your pool is to shock it with chlorine. If your pool is green, then you have little to no chlorine in your pool. You need to restore the chlorine levels of your pool in order to kill any algae and bacteria in the water. The chlorine for shocking a pool will come in granular form, so you will need to add it to a five-gallon bucket of pool water and then slowly add the water to your pool the same way you added the muriatic acid.
After a few hours, you need to go back to your pool and inspect it. In some cases, your pool may be so clean that you don't have to do anything to finish cleaning it. If, on the other hand, you see patches of green in your pool, use a cleaning brush to remove the final pockets of filth in your pool.
Once you have your pool properly cleaned, you need to make sure you don't let it go so far again that it gets green and cloudy. Properly maintaining a pool is the most important part of keeping your pool safe to swim in. Contact a business that handles swimming pool cleaning for more information.