Can I add cool water or ice cubes to a fish tank to lower water temperature in summers?

How to Cool Aquarium Water without using Chiller / Cooling Fan?

1. Using an air pump for adding more oxygen in the water due to surface agitation will release CO2 & add atmospheric oxygen in the water. Connect an air stone to an air pump via an airline to directly dissolve numerous small bubbles of oxygen in the water.
2. Open the tank cover & use a fan for cooling the water surface.
3. Add cool water to a bag & let it float on the surface of water for cooling the water. Do not quickly cool your aquarium water as fish can’t tolerate fluctuations in water temperature.
4. Do small water changes & add slightly cool water to the aquarium, but ensure that temperature does not quickly change.
5. Turn off the lights of the aquarium to lower the water temperature. But it could be a problem if you have live plants in the aquarium because plants use lights for photosynthesis.
6. If you have placed your aquarium near a window, then it is recommended to close the curtains to stop sunlight from heating your aquarium.
7. Turn on the lights for just a few hours & keep them turned off for the complete hot day to keep water temperature in control.
8. If you have setup an external filter, then it is easy to cool your aquarium. Running the tubes of the filter through cold water or through an ice box will lower the water temperature. Do not use this method in small tanks as it will fluctuate water temperature quickly.