De-gassing: When a fish tank is filled with fresh water, it contains a lot of dissolved air. As the water settles, the air bubbles come out of solution and rise to the surface. These bubbles can get trapped on the sides of the tank, especially if there are any rough or uneven surfaces.
Filter circulation: The filter in your fish tank helps to circulate the water and oxygenate it. As the water passes through the filter, air can get trapped in the filter media, causing tiny bubbles to be released into the tank.
Soap residue: If you used any kind of soap or cleaning agent to clean the fish tank before filling it, it can leave behind residue that can cause bubbles to form.
Plant debris: If you have added plants to your fish tank, they may release tiny air bubbles when they are first introduced to the water.
Water temperature changes: If the water temperature in your fish tank changes rapidly, it can cause gases in the water to expand and create bubbles.
Surface tension: The surface tension of the water in your fish tank can also contribute to the formation of bubbles. Surface tension is the force that holds the water molecules together on the surface of the water. When the surface tension is high, it can make it difficult for air bubbles to escape from the water.
To remove bubbles from your fish tank, you can try the following:
Wait: In many cases, the bubbles will eventually disappear on their own as the water settles and the dissolved air comes out of solution.
Use a bubble skimmer: A bubble skimmer is a device that helps to remove bubbles from the surface of the water. Bubble skimmers can be attached to the filter intake or outlet.
Lower the water level: If the water level in your fish tank is too high, it can create more surface tension and make it more difficult for bubbles to escape. Try lowering the water level slightly to see if it helps to reduce the bubbles.
Use a water conditioner: Some water conditioners contain chemicals that help to reduce surface tension and make it easier for air bubbles to escape.
Remove plant debris: If you have any plant debris in your fish tank, it may be releasing tiny air bubbles. Remove any plant debris that you see to help reduce the bubbles.
Avoid rapid temperature changes: Try to avoid rapid changes in the water temperature in your fish tank, as this can cause gases in the water to expand and create bubbles.