Wow! I have just now discovered that a heater exploded in my sump, it happened no more than 24 hours ago, as that is when I last checked that area of the sump. I have a blue spotted stingray and a banded cat shark in the tank, and they are showing no signs of any issues as of now, but I have been reading that some glass heaters have copper inside of them, and at this point I am not sure what to do. If there was copper in mine, would it have shown effects by now? I run carbon in the tank 24/7 so that helps, but I am still not sure what to do. The heater is two weeks old, and I have another of the exact same model that is working fine. Here is the heater in question. http://www.marinedepot.com/Hydor_TH...rium_Heaters-Hydor_USA-HD11102-FIHTGH-vi.html It is the 400W model, I could really use some help at this point.