There's a well-established rule in the aquarium hobby that says always add fish slowly (2 or 3 at a time, maybe 4 if they're really small). But explain this to me.... At the end of my "fishless cycle" I can dose my tank with ammonia and instantly bring the ammonia level up to 4 or 5 ppm. In just 24 hours the ammonia is gone completely, and nitrites are on their way out too. And yet, everyone still insists that it's necessary to add fish slowly. Why?! I find it difficult to believe that adding 10 neon tetras will cause an ammonia crisis more severe than when I dump in 10ml of janitorial strength ammonia. Will 10 or 12 neon tetras instantly raise the ammonia level to 4 ppm? Instead of the sudden rise in ammonia caused by fishless cycle ammonia dosing, I expect that 10 or so neon tetras would cause only a gradual increase in ammonia that my beneficial bacteria would handle easily. How am I mistaken? Why is it necessary to add fish slowly when fishless cycling prepares such a robust colony of beneficial bacteria?