I've done this by transplanting small amounts of water, Lemna trisulca, aquatic mosses, and netfulls of mainly daphnia and scuds. After screening for apparent leeches and other predators, this goes into rubbermaid tubs on the west side of the house, creating a home pond. Eggs and larvae can go into this, but a good screened lid is needed once transformation starts. A good growth of aquatic moss with algae sometimes will provide a "platform" for emergence. When mosquito wrigglers become apparent, I net as many as I can and feed them off to other newts in well-screened cages. Good food supply, but I prefer to keep potential sources of viruses and annoyance to a minimum, so feed before they emerge. I have used rainwater, which was fine where I was before, but could be risky elsewhere [ask Sludgemunkey].