I'm trying to do a fishless cycle on a 20 gallon aquarium set up 3 weeks ago. However the ammonia level hasn't gone down and the nitrites and nitrates remain at zero. I'm not sure what isn't working. The filter is an aqua clear 30. The water temperature is set at 80 degress. I've been leaving the light off and have the water level a bit lower than all the way to the top trying to increase oxygen flow. I haven't used any chemicals except tap water dechlorinator. I've included pictures of my test kit and the ammonia that is being used. Since I got the filter used I'm wondering if I should replace it with something better. I wanted to put used filter media or gravel in to help out, but no one else has an aquarium I can take used media from. I'm stuck as to where to go from here. Any help that can be provided would be very much appreciated. Thanks!

Did you ask your pet store for some used filter media? They'll usually give you some at no charge.

Thank you for the advice. I decreased the ammonia to about 3ppm. Hopefully this will help.