How long to let my rock "cook"

I just pulled out about 20lbs of reef saver rock I had sitting in my backyard over the summer to bleach out. It was previously used about a year ago. I have it in a 5 gallon bucket since last night with a heater and 1300gph powerhead. How long should I let it sit in there? Is 48 hours enough? 1 week? 3 weeks switching the water out every week? I guess I just want it to be safe enough to not have to worry about a sudden release of nutrients and I have never done this before.

I should mention I have a 40 breeder with about 25lbs of very well established rock (been in saltwater for over a year) and livestock in there doing just fine.