I have used different types of carbon in my tank, But, this time I did a phosphate test on the product. Turns out the Kent Marine reef carbon, new out of the container, read 2 mg/L with my phosphate test kit. I know the test kit is good, cause I get a zero reading with my RO water and I use the same RO water to test the carbon. Has anyone else had problems with Kent Marine products? Oh!, the seal was broken on the container. What's a good product to use without fear of phosphates gettin to my reef tank?