In that nitrogen cycle article from Isabella, did you read all the way down to the bottom? It gives info on a fishless cycle, which is much kinder than cycling with fish.
Since you already have fish in there, you need to monitor it closely. How long has it been set up? You should wait until you have no ammonia, nitrites, or nitrates before adding more fish.
You are getting very good advice here. Definitely get that kit. If you have a PetSmart, you may be able to go to their website, copy their add and take it to your local store. They may honor the online sale price!
When you get your master test kit, please post your ammonia, nitrite, and nitrate levels. Also, please tell us more about your tank. What is the size of your tank? Do you have live plants in your tank? This information will help us also.
I went to the store yesterday and looked at kits. I have 2 ten gallon tanks. I am wondering since I might get a 30 gallon in a week or two should I just wait to buy the cycle kit? My dad wants to buy my two tanks off of me And with tht money and the money saving up I think I will get a 30 gallon thanks