There should not be all zeros at the end of a cycle. It all ends up as Nitrates, which must be removed, so there should be some measure of nitrates. IMO
, there is no reason to do a water change during a cycle, especially if you have water with nothing showing other than phosphate.
If you pulled some live rock from an established tank, there should be beneficial bacteria. Ideally, I would dose ammonia to about 4ppm and see if it's gone in 24 hrs. If so, you are good. You could try adding a fish and watch parameters, but you've gotta have a gameplan if ammonia or nitrites show up.
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