So I've cycled my pukani for 3 months before putting it in my 90, and everything seems pretty good. I used lanthanum, and cooked it with bi weekly rinses for a while.
No algae problems a month in.
But I had some extra rock left over, and I wanted to try acid washing it. so I did, with muriatic acid. That stuff is really amazing. After the first wash, all the sponges and other slime that was really caked on to the rock, released, since the acid had eaten away most of what it was hanging on to.
After some swishing and a lanthanum rinse, the rock was >>really<< clean. I'm pretty sure that if I had done the acid wash on all my rock, I would have been able to cut down the curing time significantly, maybe down to a month.
So just for the sake of experiment, I took that rock I washed, and without curing it, stuck it straight into the tank, and a week later, I've had no ammonia testable, and parameters haven't changed at all... Now of course this is 90g and I only added a rock that was about 5lbs to 70lbs of rock already in there. So take that all with a grain of salt. But if it is leeching phosphate, I should see algae growing on it pretty soon.