1. Oxygen Deficiency:
* Why: This is the most likely cause after a water change. Even though you're using dechlorinated water, the new water may not be fully oxygenated yet. This is especially true if you used hot water to dechlorinate or didn't let the water sit for a while before adding it.
* Solution:
* Add an air stone: An air stone will create bubbles that increase the oxygen levels in the water.
* Use a water conditioner: A water conditioner helps to remove chlorine and other harmful chemicals from tap water, which can also deplete oxygen.
* Change water gradually: Don't change all the water at once. Instead, gradually replace small portions over a few days. This allows the new water to oxygenate naturally.
2. Water Quality Issues:
* Why: Even with a water change, there might be other water quality issues that are causing your betta to struggle.
* Solutions:
* Test water parameters: Use a liquid test kit to check for ammonia, nitrite, nitrate, and pH levels. These should be at optimal levels for betta fish.
* Perform a larger water change: If your water parameters are off, a larger water change can help to correct them.
* Filter maintenance: Make sure your filter is clean and functioning properly. A dirty filter can contribute to poor water quality.
3. Illness or Stress:
* Why: Your betta might be stressed from the water change itself, or they could be sick.
* Solution:
* Observe for other symptoms: Look for any other signs of illness like fin rot, cloudy eyes, lethargy, or loss of appetite.
* Consult a vet: If you suspect your betta is sick, it's best to take them to a veterinarian who specializes in fish. They can diagnose any underlying conditions and provide appropriate treatment.
4. Temperature Fluctuations:
* Why: Water temperature fluctuations can also cause your betta to gulp air.
* Solution:
* Use a heater: A heater will help to maintain a stable water temperature. Bettas prefer temperatures between 78-82 degrees Fahrenheit.
Important Notes:
* Don't overfeed: Overfeeding can lead to poor water quality. Feed your betta a small amount of food once or twice a day.
* Provide adequate tank size: Bettas need at least a 5-gallon tank.
* Avoid harsh chemicals: Don't use harsh chemicals or cleaners in or around the tank.
If you continue to notice your betta gulping air after addressing the potential causes, it's crucial to consult a veterinarian for a proper diagnosis and treatment.