it started with its fins being ragged on the end its a fantail.changed water and is now on its side not moving around. somebody help.its a 2 gallon tank and i've had it about 1.5 years. no water test kit

Hi Superfly

Sorry to hear about your poor fantail.

Firstly, I would definitely recommend you get the kits for testing ammonia, nitrite and nitrate (and ideally pH too) as you really do need to keep an eye on these: they are the best indicators of what's actually going on in the tank. Poor water quality is the most frequent killer of fish, rather than disease. The kits are reasonably cheap and very easy to use. You can also ask your local fish store to test your water for you - just take in a sample - which they will usually do for free or a tiny charge. Could you maybe do that tomorrow and let us know the results?

Also, 2 gallons is a bit too small a tank for even one goldfish - ten gallons per fish is the minimum, as a rule of thumb. Can you tell us how often you clean the gravel and do water changes? Your feeding routine would be useful too.

Ragged fins / tail is usually a sign of finrot. This is usually a bacterial infection which (sorry to belabour the point!) arises from poor water quality. It can be treated quite easily with an antibiotic or a tea-tree extract called Melafix if it isn't too severe.

However, if your fish is laying on its side and not moving then it is in serious trouble. How large was the water change and did you use de-chlorinator (also called water conditioner)? Please let us know.

the first was just a 50 % change,then we did a full change and cleaned the gravel.did not have gravel it was more like small rocks too make cleaning easier.always used water conditioner.(bowl buddy)
tank schedule was replace filter every 2 weeks, and clean the whole tank once a month.and condition the water.we feed Bob every other day.and alternated the food with flakes and floating every couple of feedings.