Just make sure you get it out of the tank fast. They release toxins into the water that are harmful to the other critters. :death:
Sorry to hear about your loss. Just make sure you don't use tap water any more. At 30 cents a gallon at walmart you can't go wrong for RO water. Also most LFS...
Here, go to this link. It will give you an idea on how to make your own base rock and what they are talking about, minus the curing of the rock in water.
making base rock