I used about 150lb of base rock which is nothing more than dry/dead LR, then used another 200lbs of really nice, fully cured LR and placed this over the base rock, looked kinda funny for about 3 weeks as the base rock was almost white, now you can't tell the difference, lots of coraline algae....Answer to you question is yes, just takes a few months.
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I would soak the base rock in fresh SW for a few days, then change the water, soak for afew more days etc..make sure you have PH's in the soaking buckets. I soak new base rock to dilute or leach out any possible contamination before adding to my tank.