non seneye testing has caused a massive, decades-long setback on being able to observe what ammonia does in a reef tank. Thankfully, we can scan logs from working seneye owners now and tell just fine how it works, and, it doesnt range in aquariums meeting certain submersion proofs (like your benthic growths) when in the presence of rocks and sand (powerful surface area)
your tank is fine, and the cycle is fine, and any new fish you add will live.
the # issue with non seneye test kits is they're not calibrated to the consistent low level free ammonia that all reef tanks convert, they're calibrated to zero and there isn't a zero ammonia measure. in my opinion that allows for just tons of variation, on a param that we have found not to vary much at all when digitally-metered. you added boosters that people use to get marine convention tanks to all start on time, without variation. yours can do that now, that a non seneye test kit doesnt agree means nothing. what it comes down to is some test kits work, some dont show low level can-start dates reliably, but all brands will show a dead fish spiking in the water/its low level measures we must use seneye to truly observe.
*reefs dont vary in ammonia control after this many days
search out anyones seneye cycling logs you'll see.
