Depends on how long a cycle takes. Some will wait till nitrites are also zero and that can take months, using way more ammonia then.
By the way, about the theory that nitrites (testing) aren't important. The scenario that nitrites will rise over 5ppm within the first couple of weeks after you added fish is not unthinkable, and in that case the (full) cycle stalls. You'll never get rid of nitrites then.
Personally i think that waiting for nitrites also to reach zero is best, because it's your only guarantee that the cycle is fully completed.
You're in the dark if you don't test for nitrites.
I agree 100% with this. Aquariums are dynamic systems that progress very differently from person to person, given the many variables that could come into play. Sure, one should not need to measure certain parameters in theory, but there will always be outliers. And given the lack of difficulty in measuring and tracking parameters, versus the headache one might experience when things do go wrong and troubleshooting is necessary.
Case in point, I was setting up an aquarium and had so much trouble with it. Theoretically, it should work fine - I had plenty of biomedia for my nitrifiers. But if I had not been tracking parameters closely, I would not have been able to really realize the issues I found and rectify them. From seemingly dud bottled bac products, to apparent effects of light on inhibiting nitrification that would normally not happen for most tanks.
So even if it ends up unnecessary, so what. It's just a few test kits and a bit of time.
Though I will say this - I think Dr. Tim is not correct with the 5ppm limitation, at least for saltwater systems.
The few studies I read has quoted higher concentrations of ammonia and nitrite needed to inhibit nitrification, though due to the lack of 'relevance' to reef systems (studying waste water treatment plants, studying species not necessarily the ones we try to seed our tanks with, etc.), I've always just kept these studies at the back of my mind.
However once I got my aquarium going, I found that nitrifiers at least from
Fritz can easily oxidize 8ppm ammonia without much issue or slow down, same with at least 20ppm or so nitrite. So it seems like the true 'cut-off' for what really inhibits at least some nitrifiers is far higher than 5ppm.
Just my two cents.