Well the tank is overstocked so poor water quality could be causing them distress.
When was the last time you performed a partial water change?
~Actually by not performing water changes you can kill the fish. Having a filter does not excuse you from water changes. The filter media gives beneficial bacteria a place to colonize and when water is circulated through, the bacteria breaks down fish waste. Ammonia becomes nitrites which in turn become nitrates. Nitrates are not broken down so a partial water change of 25% is recommended to keep levels in check and water in a healthy condition.
~I'm sorry, but both your aunt and the pet store employee are dangerously incorrect. Three years is not old for a goldfish at all. My goldfish are 13 years old, and if they don't make it to at least 25, I'll consider myself a failure.
Nitrates inhibit growth, so if the goldfish have not reached their adult lengths by this time they are stunting.
~No need to remove the fish. Just use a siphon to vacuum the gravel and remove 25% of the water. The fish will move out of the way.
Please upgrade in the near future. Black moors grow 6-8 inches and require 20 gallons for the first and 10 gallons more for each additional.
When was the last time you performed a partial water change?
~Actually by not performing water changes you can kill the fish. Having a filter does not excuse you from water changes. The filter media gives beneficial bacteria a place to colonize and when water is circulated through, the bacteria breaks down fish waste. Ammonia becomes nitrites which in turn become nitrates. Nitrates are not broken down so a partial water change of 25% is recommended to keep levels in check and water in a healthy condition.
~I'm sorry, but both your aunt and the pet store employee are dangerously incorrect. Three years is not old for a goldfish at all. My goldfish are 13 years old, and if they don't make it to at least 25, I'll consider myself a failure.
Nitrates inhibit growth, so if the goldfish have not reached their adult lengths by this time they are stunting.
~No need to remove the fish. Just use a siphon to vacuum the gravel and remove 25% of the water. The fish will move out of the way.
Please upgrade in the near future. Black moors grow 6-8 inches and require 20 gallons for the first and 10 gallons more for each additional.