Hmm, I have been using it off and on since I set my tank up with no issues. I do rinse it very thoroughly, and I only use a couple tablespoons in a 90 gallon system. How much did you use?I rinsed my phosguard and let it soak and then added it to my tank and noticed my water turn milky white. I immediately removed it and continued to rinse it and let it soak in freshwater. It’s not getting any better. Is this normal? Is it like carbon where the water will run clear? Do I have to keep rinsing it until the water runs clear? Should I let it soak in freshwater? Either way it seems to be really dusty and I assume that isn’t good.