It matters because a non-chelated copper testkit will not measure the amount of copper in the system. IME, a reading of .02 will actually be alot higher. This is one of the reasons why you can judge the bioavailability of the CU. A non-chelated kit test for free copper, where a chelated kit will test for total copper. The copper is bound to an organic this reduces the toxicity of the med considerably. I am curious, what are you wanting to use from the current set up in the reef set up, You said it was a FO
tank. Any LR
? Or just plain decorations? I personally believe that if you change the substrate (do not use the LR
) and do a 100% waterchange, you'll be fine. If you have LR
in the tank and you need to use that....I do not think it will be safe. In essence, I need more info on your system before I can offer any more advice.