FWIW - I would highly recommend getting some sponge from an established tank, if you go into your LFS (not a big box store) and ask them for some they should give it to you. Just tell them that you are cycling a new tank. Fantastic Fins will certainly do this for you!
I agree with Ron, cloudy water is normal during the cycling of a new tank. keep testing the water. Remember, cycling is a process it takes time to run through each of the steps of the process. If you want to speed up the process, go get some feeder gold fish (very cheap) and put them in the tank. this will help stabilize the process and take out the guessing of how much ammonia to add into the tank. You will loose some gold fish but who cares, they were a food fish anyways. When done cycling either take the gold fish back or throw them away and stock with what ever fish you are planning to stock.
Keep testing your tank daily until your readings are consistently zero ammonia and zero nitrites....
Good Luck !