[kanima]

I was in the process of setting up a new 55 fish only tank. It was half full when i added my live sand. I had to leave because of some work stuff my cured live rock got dropped of and my wife went ahead and added to the tank ( with out even calling and asking first). So on the way back home I had a flat picked up some nails from the consturction site. Did not get back home till almost 7 hours later. Finished fill my tank and now after 24 hours of the tank clearing I am seeing what looks like dead tiny shrimp in the sand.

Is the rock dead and usless or will it still grow stuff just not have "live critters?"

[Future]

The rock is fine. The hitchhikers don't make rock "Live". Bacteria within the rock makes it Live Rock.

This here is a good article all about our Rocks... What is Live Rock, Anyway?

[leebca]

It's unclear as to what was actually done. If the water added was freshwater, then most everything marine did die. If the water added was prepared saltwater, then most marine life should survive fine. My next question would be, if it was fresh water, what kind of water was it? (e.g., tap water, de-chlorinated water, DI, RO, RO/DI, distilled, etc.)

By virtue of the fact you have 'dead things' in the tank, I wonder what actually happened. Live rock is alive by virtue of its marine life forms that associate with the rock. The rock has different levels of being 'alive.' If all it has is bacteria, then that is base rock as well as any rough decoration with bacteria could provide.

[kanima]

It was mixed ro/di but the saltinty was high 1.028 I was going to adjust at the last 10 gallons before adding the rock. But of course that didn't happen.

[leebca]

That shift in sp. gr. may have been a shock to some marine life forms associated with the live rock. The odds are that not everyone of the species died. This would allow for those that can reproduce in the aquarium to do so. For those organisms that cannot reproduce in the aquarium, they will be lost forever.

I think you may have degraded the live rock, but not ruined it. If you are using LR in order to help control nitrates, then it should still do that. If the other bacteria (biological filter) were shocked, they will come back fairly quickly.

For help in starting up an aquarium, you should read through this post: Setting Up a FOWLR Aquarium

Good luck!