It may cause some of the critters, like bristleworms, to dislodge from the rock. As I recall, there are several processors of live rock that use a 'water spray' curing process for their live rock (Walt Smith (?) I think may be one). As long as the rock is CONTINUOUSLY exposed to seawater, I cannot think of a reason this will not work. What you don't want to happen, is have the electricity go out on the pump and your live rock dry out. Then it won't be so 'live' anymore. Keep us posted.