Problem with corals

[daniella3d]

also you might want to test for copper. I recently put Kent carbon in my tank and all my xenias (3 varieties) melted in few hours. It's not the carbon because I was using Seachem Matrix carbon before and I had my xenias thriving for the past 2 years until my tank was contaminated by copper.

Problem is, there might still be a lethal level of copper in your tank and that would be lower than what the commercial tests can detect. Anyway it is a good start to test for that anyway.