Put them in a large plasctic mixing bowl or small aquarium in the water they came in. Then take a spare piece of airline tubing and make it sihon water from the tank they are going in to whatever you put then in, and use a small "C" clamp on the tubing to slow the siphon down to a slow drip. Then just let the bowl fill up, and empty some of the water as needed. Usually about 1-3 hours is good, the longer the better.