Tank is crashing :(

[MitchM]

Glad to hear things are improving.
One thing to keep in mind, depending on how old your live rock is, it could be contributing an extra amount to your detritus buildup through a process called bacterial turgor.
Basically, turgor is when the pressure builds up in bacterial cell walls and forces waste products out.
The bacteria in the top few millimeters of your live rock could just be cleaning out the old live rock.