I hope this will help everyone understand How Important the cycle of a tank is. You can kill many fish if you don't check the levels of the tank (feed them too much and adding to many fish to the tank).

You need a fish in the tank to start the cycle. Most people use a common, or comet goldfish since they are more harder than the Fancy type goldfish!!!!

When first setting up a tank it goes like this: Ammonia levels go high for the first 10-14 days, then the Nitrites kick in at very high levels for 10-40days this is where most people lose there fish. Then slowly the Nitrates kick in30-40 days. After the first month the tank should be cycled but you need to get a kit and check for all of these. I also recommend a log. I have a log that I write down all my tests in just in case something goes wrong I can go back and see what might have happened.

The ammonia levels will go through the celling if have to many fish and adding to much food.

Then the nitrites: Once the tank is cycled and maintained the nitrites should go down. Nitrites and ammonia are deadly at a high levels and will kill your fish very fast and quickly.

Nitrates: This is the last part of the cycle. This can make your goldfish sick in a slow way if you don't have a filter and change the water. Live plants like to eat this and helps keep it down but you have to do water changes.