phosphate and adding dry rock

[Magickiwi]

Most of the rock that went into my large tank was dry rock. Buying 90+ lbs of live rock wasn't in the cards @ $10-$12/LB. Honestly I'm disappointed with how slowly the coraline is growing on the dry rock and I do have sky high phosphates.

I think my problem with phosphates was due in part to using tap water for set up and over feeding. So I don't attribute it to the dry rock.