A good hatch will depend on a few important criteria, and at the prices of eggs, getting the best hatch you can, will save you substantial amounts of money.
First, pH in the hatching container should be over 8.0 during the full hatching time. Many people's water will have the pH fall drastically during the hatch-out, so you should test it after 24 hours of incubating the eggs. You can use some epsom salt and some pH Fixit 8.3 to get it where you need it.
Second, salinity should generally be high. 1.023 to 1.030 on a hydrometer is the range you should try for. Some eggs will hatch better in different salinities than others. Measuring tablespoons per liter doesn't work. You need a hydrometer to get this right. After you have determined the correct amount of salt for that type of salt, you can use a measuring cup to get the salt correct.
Third, temperature should be approximately 80 degrees F. If the container is too hot, the shrimp will not hatch as well and it will die easily. If it's too cold, then hatch-out times can be delayed and hatch-out percentages will fall. It is best to keep the hatching containers in a temperature controlled room or box. Below is an example of a hatching box that uses low wattage bulbs to control the temperature. Temperature can be varied by using different watt bulbs and putting a door on if the room is too cold. The bulb in this box is a 7 watt fluorescent. The second photo show the hatch-out of our typical Premium-Grade with the bulb turned on.
Enough aeration is necessary to keep all the cysts suspended. Any that remain on the bottom will not hatch. When artemia hatch, they consist of mostly a yolk sac. As the hours go by, the artemia consume the yolk sac to stay alive and in the process they become less nutritious. Also, as time goes by, dangerous bacteria will grow on the shrimp. Eventually it becomes dangerous to feed. For these reasons, artemia should be fed as soon after it hatches as possible. It should not be stored for future feedings. Hatch only enough at one time to feed all the fish at that feeding. Then restart the hatchery with fresh water, salt, and cysts. Clean the hatching container very thoroughly before starting the next hatchout.
To harvest, remove aeration and let the hatched artemia settle to the bottom. Then siphon this out through a brine shrimp sieve, rinse with fresh water into a feeding container and then feed using an eyedropper or turkey baster.
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