Why is treating ailing fish with copper still one of the go-to methods for aquarium keepers these days? Copper-based medications are extremely harsh on fish, corals, and invertebrates alike. Sure, some fish can withstand coppper treatments in higher concentrations and for longer periods of time, but that doesn’t mean it’s any less harsh on the animal. In fact, some species of fish can’t be treated with copper at all. For alternatives, we suggest you start by buying a healthy fish, quarantining that individual for several weeks, feed copious amounts of highly nutritional foodstuffs, and if necessary, treat any ailments with less harmful medication. Heck, even freshwater dips for fish would be better than long term treatment with copper.