best way to get old dead rock white again???

[demon666]

ok kool i picked some up lastnight and have to do a water change today of tommorrow so ill start adding it then i really dont want to start at green rocks in my tank pink and purple would be way nicer

[clipperfish]

Hello . I bought some live rock from someone .awhile ago and it was covered in green alge and hair alge . what i did was cook it for three months in a tub of saltwater with no light at all .the alge disappeared altogether .And I change 50% of the water weekly .it might not take that long but i was moveing so i left it for three months .hope this helps .