Have you ever thought of trying bio pellets?
To be honest, not really. I guess I started reading all the threads about them when they first came out and with all the problems and never really looked past that. I have been contemplating either a completely swap out of live rock (slowly) or adding another tank to the system full of live rock. I'm kinda leaning towards the first choice, and then clean the dry rock with whatever chemical helps the phosphate issue with dry rock and then adding it back to seed it.