I just did this about 3 weeks ago with my reef tank! I had coarse crushed coral for about 5yrs and also wanted to go with live sand because i like the look better. It was so coarse that i wasn't able to have any sand sifters either, which i think caused some issues as well. My trates started to act up a bit and no matter how many PWC
I did, it was fighting me. I was told that the CC "could" be the culprit but it was never confirmed....although i don't have any nitrates any longer. Take that how you will.
so after I transferred 110lbs of like rock, corals, and 4 fish with a refugium with a deep sand bed (which i did NOT disturb) and had absolutely NO ammonia spike whatsoever. I really enjoy the change AND it's kind of renewed my interest again, so win win. That being said, what you want to do can definitely be done with 5gallon buckets, and some coolers.