Kent marine reef plus vitamins

[Oceanicsublimat]

I have been using small amounts of this stuff in my shrimp and scallop mush for about 2 weeks now and the fish seem to be more colorful.. however my concern is that I was reading on the back of the bottle and the contents reads that there is a small percentage of copper in it(.001mg) granted this is not a significant percentage, but could there be any adverse effects on my inverts if used for a prolonged time?