

The accumulation of copper sulfate after application can create a sterile water bottom where important nutrients and bacteria that fish and other aquatic life need are killed off.

As stated above, copper sulfate accumulates as a heavy metal precipitate once it is applied to water. Thus, using copper sulfate will create more work in the end. It also accelerates the recycling of phosphorus which can promote algae blooms as well. This accumulation of copper sulfate and the decaying algae leads to the release of toxins and can result in the accumulated mass to resurface or “rebound” to levels similar, or higher, than the original bloom. It quickly sinks once applied to water, which causes it to accumulate as a heavy metal precipitate. It is more likely to contribute to rebound blooms.The potential damage to human health far outweighs the benefits of curing an algae bloom. Ultimately, copper sulfate is an unnecessary risk to those who dispense it. These risks are documented by the EPA who have classified copper sulfate as a class 1-highly toxic chemical, which requires a poison warning displayed on all labels. Additionally, if ingested (through inhalation of the powder or through drinking it) copper sulfate can cause immediate vomiting, and if retained in the stomach: unconsciousness, burning pain, nausea, diarrhea, headache, shock, and unconsciousness. If contact occurs, it can cause itching and permanent yellow discoloration of the skin.
COPPER SULFATE SKIN
Since copper sulfate is easily absorbed through the skin, those that dispense it must be extremely cautious to avoid even minimal skin contact with it. When used to combat algae blooms in water, copper sulfate can create a hazard to humans. For this reason, copper sulfate becomes ineffective-it kills the algae, which then sinks to the bottom of the pond where it decays and releases additional toxins which can create more blooms, essentially resulting in a larger problem than you started with. Instead of targeting the nutrients that cause the algae to grow in the first place, it only targets algae itself. When it is applied to an infected water location it can treat only the visible symptoms of algae.
