The cool thing about ammonia is you can predict it without a test kit 100% of the time if you can account for life in the tank (no decay)
The true formula is: does bioload stay alive two days, if so Ammonia cannot read in the tenths if the provided surface area is typical rocks and sand. Anything below the tenths ppm and you're safe, but only seneye can measure it well, perhaps mindstream too. My thread proves with seneye what ammonia will be when bioload thrives, no testing across tanks required, it doesn't range. Just be doing water change feed, water change feed, like CPR and simply drive growth in the corals.