That’s good to know. Although I think this will not be a problem, one of my clean shrimps did die yesterday and I have them for the past 9-10 months. I found the fish were picking at what was left of it overnight. I am not sure it was predation or it was copper levels causing it to die.For what it is worth, I found some cases that these copper testers reported copper levels from other brands of salts including Coral Pro at 0.05 ppm to 0.3ppm.