can someone please answer this question about copper

[JVH]

The problem is you have an incompatible test kit for the type of copper you are using.

Salifert and Seachem copper test kit only measure in the low range. These cater to Cupramine, which is ionic copper designed to be effective in the low range of 0.35-0.5 ppm.

Coppersafe and this "Kordon Copper-AID" you are using are chelated copper, a completely different animal. Chelated copper is only effective in the high range of 1.5-2.0 ppm. So, to measure chelated copper you need a "total copper test kit" such as API copper test kit.

Well that's what I thought but after the test didn't show anything I went on line to the company and found this:
The Salifert test kit offers a very sensitive and accurate test for measuring dissolved or weakly chelated copper with a pH of 7.5–9.
But, I guess I need to get the API. I have been slowly replacing my test kits because I heard API is not always accurate.. So of I avoided that for this test.. Il get another test and see what happens...Any idea why the fins would be getting frayed? Could that be a side effect of the copper?

 

[Humblefish]

Any idea why the fins would be getting frayed? Could that be a side effect of the copper?

Could be a secondary bacterial infection setting in. Very common in fish with ich.