I am sorry but I would tend to dissagree with Bamaboy on this one.
Rocks contain minerals that can and will be leached into SW
aquariums much differently than FW
aquariums due to the chemical nature of SW
. Take for instance copper, this will not effect a FW
aquarium in a negative way (to my knowledge, I could be incorrect here) but even a small amount of copper in a SW
aquarium will make the aquarium uninhabitable by any invertibrates which are the backbone of a SW
reef. Other rocks contain Silicates and other undesirable minerals, the reason most everyone uses lr
from reefs is because they are coral skeletens and we are relatively certain they are safe for other corals.
If the "white holey rock" is sandstone for instance I would say no way would you want that in a SW
aquarium. But if it is old coral skeletens I would say after cleaning they should be fine.
Bottom line, If you don't know for certain, don't use it
Post pics of the rocks, I am sure someone can probably id it for you.