f1 vet should remember a talk we had like this my tap water has 1ppm ammonia in kc so its not unheard of. the kc water quality report shows they test it at 0.72ppm so that likely shows up as 1 on my api. I never have any problems doing water changes in fresh water tanks with tap water that is around 1ppm ammonia. Now the only catch i had was if something happened like equipment failure or power outages ect that caused a mini cycle. so since the tap water itself has ammonia if trying to do a water change to bring down ammonia due to a full or mini cycle you have to change much more water as your not removing as much ammonia. also prime only detoxifies ammonia it doesn't remove it.