Thrive Aquatics Bio-Stimulant Crush 3.5 Gallon， 13.24-Inch， Large</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>Blend of two different polymers as well as aragonite</li><li>Great surface area for bacteria to colonize</li><li>removes nitrates and phosphates in your aquarium</li></ul></div></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br><img src='http://ecx.images-amazon.com/images/I/41zQtbWfIqL.jpg' noproxy></br>