Yep that can work.
The step down removal increments that people do to let bacteria adjust are not required, that's a harmless safety hedge aquarists invented but it's not factoring the bacteria left on the rocks and other surfaces which can still digest a few ppm in 24 hours like any tank would that's cycled.
Your danger is surprise rot or detritus exposed to sensitives
None of that filth exists in my tank that's for sure. I can flip my reef like a pancake on demand and often make threads of it.
Sandbed bac are incidental not deal breakers for nitrification
Agreed that to avoid ammonia liberation (if applicable/na for clean tanks like mine and yours, my six inch sb will pass a drop test) incremental removal is safe but only if the keeper has a reason for not doing all at once, our whole thread is built on all at once deliberate action.
Bare bottom keepers have their live rock as the basis of their filtration not because all of a sudden fifty new layers of nitrifers built up to cover loss of the sandbed
-not microbiology-
It's that the already colonized active surface area of the live rock beforehand was vastly beyond the minimum requirements of the tank, no extra was needed, then we compounded the heck out if it further by adding high surface area sand, which we then removed and are still left with excess active surface area. They could then remove half their live rock and the system will still run the original bio load, from the sandbed condition and ramp time is not needed
The leftover surfaces do not take on extra layers galore of the same masses of bacteria
They were already sufficient and continue based on surface area available, the bac don't just setup and move to the leftover rocks, competitions exist to stop that in real microbiology. How low each tank can go on active surface area values varies but I bet any tank here can run on 1/3 of the current rocks alone and be fine.
if you can be positive that not rot will be kicked up, what you do to the bed does not matter. Rip it all, rip a third, put a new, put a partial, all incidental and in that means you are free to act safely
Very soon I will take my reef apart, wash the whole sandbed in peroxide and scalding tap water, then cool saltwater final rinse, then reassemble it all within 20 mins like new, and go ahead and opt out of the recycle. What's more offensive to sandbed rules than that heh
