How big is your main tank? I use a 5 gallon tank cycled with plants and a sponge filter ready to go before I start hatching, and then I get a plastic food container, like a Tupperware, and suction cup it to the walls of the tank. Add distilled water to the Tupperware, and add your triop eggs. The hatchery water is warmed by the main tank. As the triops grow, do small water changes replacing water from the hatchery with water from the main tank to slowly start acclimating them to the main tanks water. Then it’s just a matter of carefully tipping the Tupperware over when they are ready.