Which term describes a tank system that does not exchange water with the environment?

Which term describes a tank system that does not exchange water with the environment?

• A. Mixed system
• B. Open system
• C. Closed system
• D. Flow-through system

Answer: (C)

Understanding water exchange in tank systems: a closed system is one that does not exchange water with the environment. The water stays within the tank and is continually recirculated through filtration, aeration, and treatment processes. Because nothing from the outside replaces the water, maintaining water quality becomes essential, relying on mechanical and biological filters, pumps, and routine chemical monitoring (such as ammonia, nitrite, nitrate, pH, and dissolved oxygen). This contrasts with an open system, which constantly exchanges water with the surroundings, introducing fresh water and removing used water and contaminants; a flow-through system brings in new water and discharges it after a single pass, so there is some exchange but not full recirculation. A mixed system isn’t a standard term for these configurations.

Understanding water exchange in tank systems: a closed system is one that does not exchange water with the environment. The water stays within the tank and is continually recirculated through filtration, aeration, and treatment processes. Because nothing from the outside replaces the water, maintaining water quality becomes essential, relying on mechanical and biological filters, pumps, and routine chemical monitoring (such as ammonia, nitrite, nitrate, pH, and dissolved oxygen). This contrasts with an open system, which constantly exchanges water with the surroundings, introducing fresh water and removing used water and contaminants; a flow-through system brings in new water and discharges it after a single pass, so there is some exchange but not full recirculation. A mixed system isn’t a standard term for these configurations.