Do you mean you have been using fish to cycle?? If so DO NOT add ammonia - it'll kill your fish! If you havent been using fish then how long is it taking for your ammonia to drop from 4ppm to 0ppm???I have been doing a fish in cycle
Have you checked the nitrAte level in your tap water?Ammonia: 0ppmNitrites: 1ppmNitrates: 5ppm