Here are some other reasons your fish might be dying even with good ammonia levels:
Water Quality Issues:
* Nitrite: Even if ammonia is low, high nitrite levels can be deadly. Nitrite is a byproduct of ammonia breakdown, and it's toxic to fish. Test for nitrite levels regularly.
* Nitrate: While less toxic than ammonia or nitrite, high nitrate levels can still stress fish. Test for nitrates and perform regular water changes to keep levels in check.
* pH: The ideal pH for your fish species is crucial. If the pH is too high or too low, it can cause stress and make your fish more susceptible to disease.
* Temperature: Fish are sensitive to temperature changes. Make sure the water temperature is within the optimal range for your species.
* Dissolved oxygen: Fish need dissolved oxygen to breathe. If your tank is overstocked or poorly aerated, oxygen levels can become too low.
* Chlorine/Chloramine: Make sure you are using a dechlorinator to remove chlorine and chloramine from your tap water before adding it to the tank.
Other Factors:
* Disease: Your fish could be suffering from an illness. Observe their behavior and look for any signs of disease, such as fin rot, white spots, or lethargy.
* Parasites: Parasites can weaken your fish and make them more susceptible to other problems.
* Stress: Fish can be stressed by factors like overcrowding, loud noises, or poor water quality. This can weaken their immune system and make them more prone to illness.
* Poor diet: An inadequate diet can weaken your fish's immune system and make them more vulnerable to disease.
* New Tank Syndrome: If your tank is new, it might not be fully cycled, meaning the beneficial bacteria that break down ammonia haven't established themselves yet. This can lead to sudden spikes in ammonia and nitrite, even after initial testing shows good levels.
Troubleshooting Tips:
* Test all your water parameters: Use a reliable test kit to measure ammonia, nitrite, nitrate, pH, and dissolved oxygen.
* Perform a large water change: Replace a significant portion of the water (25-50%) with fresh, dechlorinated water.
* Check for signs of disease: Observe your fish closely and look for any signs of illness.
* Improve aeration: If necessary, add an air stone or increase the flow of your filter to improve oxygen levels.
* Consult a veterinarian: If you're concerned about your fish, take them to a fish veterinarian for diagnosis and treatment.
Prevention is key:
* Cycle your tank properly: Before adding fish, ensure the tank is cycled. This involves allowing the beneficial bacteria to establish themselves in the tank.
* Maintain good water quality: Regularly test water parameters and perform water changes.
* Feed your fish a balanced diet: Choose high-quality food appropriate for your fish species.
* Avoid overstocking: Don't overcrowd your tank. Give your fish plenty of space to swim.
* Provide a stress-free environment: Keep your tank clean, quiet, and at a stable temperature.
By addressing the potential causes and taking preventative measures, you can help ensure a healthy and happy environment for your aquarium fish.