Yes exactly I'm having a hard time counting the right amount of Prime to use in my new water and adding too much I am overdosing believe it or not. This causes my fish to gasp and my ammonia to shoot up. It's very upsetting to see and since I need to change my water I'm unsure WHAT to do now! I think the dropper idea is good. My fresh water bucket holds 4 gallons of water and I have to work with that. I have to resolve this problem somehow and right now I'm pulling my hair out! Oh and yes city water but I tested the tap water it has no ammonia in it, it's when I add the prime that I get an ammonia reading, go figure!