Spa Choice 472-3-3061 Increase Calcium Spa Chemical， 1-Quart<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Spa Choice Increase Calcium is used to increase calcium hardness in spas and hot tubs in areas with low levels of hardness</li><li>Low hardness will etch plaster and corrode spa equipment</li><li>The ideal hardness level is 200-400 ppm (parts per million)</li><li>Downloadable User Guide Available Under Product Information: Technical Specifications</li></ul></div><img src="http://ecx.images-amazon.com/images/I/4129Pfqc1yL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51J7Y07v8OL.jpg" noproxy>