something amazing is also true
you could put up that nitrate test kit and never use it again, along with any other test kit other than calcium and alk. no joke, try to imagine how the last week would have gone down having never tested for it at all and thinking it was part of any problem. this is the classic reef misdirection starting early on for you, cast it out.
By removing the sandbed, you've removed the only thing that w spike your nitrates and the reason we don't need a test is because you can test the levels by watching the natural algae that develop on the rocks (that you kill, so it never takes over) if you start to get some algae, work on finding detritus and waste stores in the tank better, remove them, and just kill off the algae. A testing reduced reef is much easier, we trade that off by simply doing better water changes weekly or bi weekly
you can get farther in reefing knowing what to test for and not test for, putting efforts where they really matter and export of waste is what really matters, you can do that better now. I would never recommend any action to a reefer than I haven't already been doing 15 yrs. the reason you also don't need an ammonia kit is because in that type of aquascape you can account for all fish all the time, so if one dies you can see it. its still ok to keep an ammonia test as backup, but the point is testing in general. if you aren't going to do large water changes then test for calcium and alk, if you are, then you don't have to test for anything but temp and salt levels. thousands of us do it this way.
I stated all this in prep for your greatest challenge yet, coming in a couple mos or less, green hair algae. you'll have a clear choice then; chase nutrients, tedious testing, no direct action on the algae and about half w be ok w that, or direct kill on the algae when its the size of a thumbnail on day 1 where 100% have a great outcome with that, and they don't care what their nutrients are because they keep a clean tank...
a choice is coming
