Is lace rock safe for a saltwater aqaurium, we have fish and reef set up?

Answer 1

If this is the same rock sold as lace rock at my local stores it is safe. This is just a calcium carbonate rock that's porous with some rather large holes, so it's made of similar material as the limestones that form in deepwater environments.

I recomend things like lace and dry reef rock to use at the base of rockwork for marine tanks because it's less expensive, then stacking good quality live rock on the top and in front. The organisms that can survive without as intense of light will eventually colonize the dry rock (as will the nitrifying bacteria), and you don't have the cost or die-off of using live rock throughout.

Answer 2

Yes it is fine.