For ammonia, you can go to your local grocery store and buy a bottle of house hold ammonia. Just make sure it's not the scented type cause those additives can be harmful to the fish you mean to put in there once the cycle's over with. Useing ammonia, you can also better control how much you put in there, and it's quicker than waiting for food to rot. Putting a lot of ammonia in can also allow you to put more fish in at once when the cycle is done as that will cause a larger colony of benificial bacteria to grow. Like Sharks said, you don't want to do any water changes while fishless cycling. The only one you want to do is when the cycle is done, and ammonia and nitrIte readings are at 0. When the cycles done you will have a large ammount of nitrAtes. You will want to do a large water change or two to get rid of that. Good luck with your cycling! When I did my first fishless cycling on a 10 gal, it took a month and a half!!! Now I can cycle a tank in a couple of weeks though. Experience is the best teacher.