Live rock Help 20lb chunk

[gregzz4]

Cooking rock, as in using heat or drying it, will do nothing for PO4 removal. All it will do is kill all the life, thus creating a bunch of stuff you'll need to remove such as NO2-3, NH3 etc, plus more PO4
Once the rock is dead, you'd still need to 'cure' it to remove all that residual stuff that's trapped inside all the micro pores

'Cooking LR' is the process of curing it and, as mentioned above, can be found on the web, but Myka has written a nice bit for you to read

http://www.canreef.com/vbulletin/showthread.php?t=44859

It can take weeks, but more likely months, for you to get your LR to acceptable levels
Using phosphate removers in the tub (with a heater and powerhead) will definately help, but it still takes time for the PO4 to leach out of the rock

You could always look for another piece of LR, but test the water before you buy it

Good luck