Which one of the following statements with regard to growth of coral reefs is not correct?

Coral Reefs can grow only in the clean salt water of oceans, which lack any kind of instability.

• Corals thrive in tropical water with a temperature between 23°C-25°C.
• A fair amount of sunlight for survival.
• Ideal depth between 45 m to 55 m.
• No marine pollution.
• Corals need saltwater to survive and require a certain balance in the ratio of salt to the water. This is why corals don’t live in areas where rivers drain freshwater into the ocean.