Saltwater pools become cloudy after heavy rainfall and heavy use, like long pool parties, because the pH level becomes unbalanced. When the pH level in a pool is too high or low, the chlorine is unable to break down dirt and other debris to keep the pool clean. A quick test of the pool water will tell you what you need to do to get your pool water balanced. Test your pool water weekly and balance the pH and chlorine levels as needed.
Test the water with a pool test kit. Follow the test's instructions and take samples from your pool with the test tubes. Add the recommended amount of testing solution and compare the color of the water to the chart included with your kit. Check the pH level of your pool -- it should be between 7.5 and 7.8.
Add baking soda if your pool water's pH level is too low. If the pH is below 7.2, add 3 to 4 lbs. for every 10,000 gallons of water. If it is between 7.2 and 7.5, add 2 lbs. for every 10,000 gallons of water.
Add muriatic acid if the water's pH level is too high. Pour in 1 lb. if the pH level is between 7.8 and 8, 1.5 lbs. if the level is between 8 and 8.4 or 2 lbs. if it is above 8.4. Pour the acid into the pool at the deepest point.
Wait 24 hours after adding either muriatic acid or baking soda. Use a chlorine shock treatment if the water remains cloudy after this point. Add the chlorine shock treatment as directed by the instructions on the bottle. The chlorine will break down the materials that are making your water cloudy and eventually evaporate from the pool. The amount of time you must wait before getting into the pool varies from product to product, so read the packaging for the recommended wait time.