Unactive fish

Question
My Calico goldfish is suddenly less active than usual,do you have any suggestions I could try?
The tank is a year old.I have only the one fish.
It is a tank of 10 gallons.I have an air pump and
an aeration rock. I do not mesure the pH,ammonia
or nitrite levels,however I never did all this
time and he was fine.

Answer
Hi Denise;

Make a 25% water change and get the water tested. Check the fish all over for signs of parasites or other disease. (Is the belly larger than normal?, are the eyes cloudy?, do the scales look like they stick out?, etc.) If there are no physical signs of disease there could be a water chemistry problem. It could be pH that is too high or too low, or it could be elevated ammonia, nitrite or nitrate.

Also check the water temperature. If it has gone down recently the fish will become less active. If the tank has no heater (goldfish don't need one) the tank water will be the same temp as your house. Has your house temp changed recently?

Followups welcome

At Your Service;
Chris Robbins