Dry Pukani will leach phosphates... there’s tons of dried dead stuff on there. Soak it in a brute trash can with RODI water for a couple of days, it will stink... badly. Change the water every couple of days and repeat the process for a few weeks until the water doesn’t stink any more. Then soak in heated saltwater and test for phosphates. It will be sky high. If you’re not in a rush, change the saltwater every week for a few months until the phosphate readings go down. To speed up the process, dose lanthum chloride (commercial strength SeaKlear). Lanthum chloride dosing is detailed in this long but very informative Pukani dry rock curing thread.
http://www.reefcentral.com/forums/sh....php?t=2049855