From my experience with sea monkeys, or brine shrimp, it’s common to face the challenge of them hatching fine but dying off shortly after. I've tried varying the water conditions extensively, including adjusting salinity levels, monitoring food quantity and quality, and ensuring proper aeration. One key insight I learned is to be very precise with salinity. Sea monkeys thrive best in water with a salinity of about 1.018 to 1.022 specific gravity. Too high or too low salinity stresses the shrimp and can lead to mass die-offs. Another important factor is the feeding schedule. Overfeeding can pollute the water quickly, while underfeeding leaves the shrimp weak and stunted. I found feeding them a tiny pinch of powdered brine shrimp food or finely ground fish food every other day works well. Additionally, using an aquarium air pump to maintain gentle aeration keeps oxygen levels sufficient and prevents the eggs and shrimp from settling at the bottom and suffocating. It’s also invaluable to maintain consistent water temperature—between 72°F and 78°F is ideal. Rapid temperature changes can shock your shrimp and shorten their lifespan. Patience is key as well; after hatching, sea monkeys may need a week or more before you see them thriving visibly. If you’re struggling with sudden losses, consider testing your water parameters with a kit to monitor pH, salinity, and ammonia levels. Keeping the tank clean and performing partial water changes weekly can greatly improve their survival. In summary, success with sea monkeys requires careful attention to water quality, feeding, aeration, and temperature. By optimizing these factors and observing their behavior daily, you can enjoy the fascinating experience of watching these tiny aquatic creatures flourish in your aquarium.