Answer: "I get asked this question a lot. The technical definition of a herbicide is any agent or chemical compound used to deter, control or eradicate a herbaceous plant that’s deemed a pest to humans, environment, or livestock. But basically, herbicides are used to treat specific plants to produce a specific outcome. So, herbicides generally do not affect algaes or other aquatic life outside of that category. So the word “herbicide” is specific to herbaceous material."