Nitrate-less cycle?

ok, here’s the deal: just set-up a 120 with dual mega-flows, 30g-ish sump. fritz RPM salt. about 80lbs of dry rock in the tank. 20lbs or so (small pieces) in the sump. 100 lbs or so of arag-alive live sand. then around june 25, 3 1/2 weeks ago, i dosed dr tims ammonia chloride. few days later, the dr. tims one and only. ammonia spikes went down after a week or so, completely gone in 2 weeks. in the middle, obviously, the nitrites spiked of the chart and disappeared after about 2 weeks as well. so ive been around 5 days or more since the nitrites zero’d out and i have nothing more than 5 ppm nitrate. its between 0 and 5 in my opinion.
anyone ever see this? Any idea why? Pretty safe to assume i may see a small cycle after i start adding livestock?
few notes that i think may have affected it…
1- i didnt ghost feed. so the bacteria that consumed the nitrite died? but they still would have excreted nitrates in the process i would think.
2-ive been running the skimmer the whole time. could that have affected the cycle?
or, 3- that live sand and “one and only” combo was so potent it knocked the ammonia/nitrite out with very little nitrates? i still would have thought whatever consumed the nitrite HAD to have dumped nitrates in the water column…

Skimmer could have pulled the nutrients out to an extent. Never ran a skimmer during cycle so i have no experience to base it on though. I have never fishless cycled either though. I am an oldhead and have always started my systems with stuff from other established systems and did the typical start with one fish after a week. At 2 weeks test add some inverts, at 3 weeks test and so on. Then i always added livestock extremely slow to allow the system to catch up to each addition. I mean obviously i wouldnt cycle now with fish given the options we have available.