It's a great big terra-cotta bowl that holds about four gallons of water. I put some clean aquarium gravel in the bottom and added a water lettuce, a water hyacinth and an umbrella sedge plant from the fish pond. I figured there was enough algae on their roots to sustain the tadpoles once they'd hatched, and we'd go from there.
Meanwhile, another rescue was in progress. For while these eggs were hatching, some big puddles in the driveway were perilously close to drying up. And those would give us one of the best gifts of the summer.
Time to make another tadpole habitat! This one was a little water garden dish made of plastic, about 18" across and 4" deep.