@Hans24hrs - IMO your tank crashed because of high phosphates, as it is known that phosphates are inhibiting coral calcification at this levels - more info here (Randy's article ) - http://reefkeeping.com/issues/2006-09/rhf/#5 . And now you are struggling to keep SPS just because your new rocks are "to young", and not because of phosphates. From my experience dry or artificial rocks needs few months of stable environment to mature. Even if we dump dead rocks in the ocean it will took several months prior corals to decide the rocks are good enough for them . My advice would be to chose only one method for phosphate export, f.e. NOPOX or other ethanol:vinegar method is just fine and will remove phosphate als. Try keeping phosphates not rising (no need to lover current levels), and to keep nitrates detectable, and I'm sure you will have happy SPSes in few months from now.