If you have come here you're most likely looking for information on how to take care of your goldfish. We have plenty of information on how to get started and how to help your goldfish have a long, healthy life.
There are many things you need to know before you get started. Goldfish have special needs compared to other fish, for example fancy goldfish needs 10-15 gallons for one fish, with an ideal minimum tank size of 40 gallons having very good filtration.
Goldfish don't live very long in a Bowl. Why?
1. Not enough air surface in a bowl.
2. No filtration at all in a bowl.
Cycle Of The Tank
Cycling of the tank is necessary to raise goldfish. So you've got a 40 gallon tank and you just got the tank home with no fish at all at this point. Well the first thing is to set the tank up. In short terms setting up the tank is placing water into the tank, rocks, filter, chemicals, and plants if you want to. Now once the tank is all put together you will need to let the tank run for at least 24 hours before adding the fish.
After 24 hours of running with the filter in the tank, you will need a fish that will help cycle the tank. I wouldn't get your goldfish right now, there are Danio's that are very hardy fish and they can take they cycling of the tank better than the goldfish can. After you add the fish in to the tank I would strongly suggest getting a test kit so that you can see the levels of ammonia, nitrites and nitrates in the water. This is going to be the only way for you to find out if its safe for you to add the goldfish to this tank.
Okay, so now the fish is in the tank and your wondering whats next... Well now we get into the cycling of the tank. The cycling of the tank is simple but can be complicated. So I'm going to try to make it easy to understand.
The first thing that's going to happen to the tank is the ammonia is going to get very high, this is caused by the fish waste (food, plant decay). You will need to test this, because if the levels get to high the fish can die of ammonia poisoning (blood poisoning). You will need to make sure that the level stays below the 1.0 mark on the test kit. The way to help this level if it gets to high is small water changes every day of at least 20-30% this will help to relieve the ammonia level off of the fish.
The ammonia level will rise until about the 10th day, the nitrites will kick in around the 10th day also. Nitrites can be just as dangerous as the ammonia levels. Nitrite bacteria basically convert the ammonia into nitrites. If the level of nitrites gets above the 1.0 mark on the test kits you can get Nitrite poisoning (fin rot, flashing, bacterial ulcers etc.). This level can be controlled to by small water changes of 20-30% when you test the water.
After about 20 days the next level of the cycling will happen: Nitrates. This is not harmful like the others. The only other thing that you will need to do now is regular water changes. Now you can add your goldfish.
One thing to remember, tanks at temps 78*F will cycle in about 30 days, tanks with lower temps will take much longer to cycle.
I have found over the years that changing 50%-60% of the water every week is very important, because of the large amount of waste they produce and the oxygen they use. When replacing the water you need to treat it with a detoxifier. I highly recommend either Prime or Amquel, it gets rid of toxins and also doesn't turn the chlorine to ammonia.