Pool Basics 2302PB pH Lower for Swimming Pools， 2.5-Pound<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Add to the pool when the pH level is outside the ideal range of 7.2 to 7.8 ppm</li><li>Water balance is important for other chemicals to work effectively</li><li>Prevents scaling， calcium deposits and cloudy water conditions</li></ul></div><img src="http://ecx.images-amazon.com/images/I/312iKFwO6wL.jpg" noproxy>