Your reef tank never got it's storm/export cleaning when the invasion began. Look at how Paul, with the longest living tank here, must act on pore-clogging detritus, at least annually, with his big diatomaceous earth vacuum filter. It's time to take your tank apart, make it cloudless (where shaking rocks or picking up sand in the tank makes no cloud) + put it back together without losing anything.
The type of primary invaders that capitalize on the pent up cloudy waste stores in the rock, on the sand, range tank to tank. All fed by the same substance.
Your tanks challenge is not chemical nor does ID matter in beating that invader. Clean it, save it, then stock it with fancy pods from algen as preventative