Which substance is known to be non-toxic to aquatic organisms and acts as a good viricide?

Ozone is recognized for its effectiveness as a viricide while being relatively non-toxic to aquatic organisms when managed properly. It functions by generating free radicals that can alter the structure of viruses, leading to their inactivation. Because ozone decomposes rapidly, it does not leave harmful residues in water, making it a desirable option for water treatment systems focused on maintaining aquatic health.

In contrast, calcium hypochlorite and chlorine dioxide can pose toxicity risks to aquatic life when introduced in significant concentrations, often leading to harmful effects on various species. Sulfur dioxide also presents risks, particularly due to its solubility and potential to form acids in water, which can be detrimental to fish and other aquatic organisms. Thus, ozone stands out as the best choice for its dual role in controlling viruses while minimizing risks to aquatic ecosystems.