The very first tank aside, is cycling a new tank an art or a science?
I'd been thinking about this, maybe too much, but between the two options, here's my impression:
Science would imply that there's a particular set of rules which sets a protocol to be followed and only upon verification of cycle completion would you stock fish.
Art strikes me as personal judgement of the execution cycling a new tank and when fish should be added based on prior experience.
When I do it, I use factual knowledge of the factors involved, theory of the process, and execute without ever using measurement or testing kits to validate just what the ammonia, nitrite, and nitrate levels are. Thus, I believe my implementation is more of a science.
Upon further consideration of those who do use test kits, I also suspect that the argument still exists that it's an art, because you've got to place match-maker when staring at those color charts trying to decide which is the best fit and it strikes me as imprecise none the less.