Hatching and Harvesting Tips for GSL Artemia Cysts
- Hydrate artemia cysts: This shortens hatching time and disinfects the cysts. This is done for one hour in a 5 – 15ppm chlorine solution with very strong aeration, making sure that all cysts get exposed to the chlorine solution.
To hydrate one pound of artemia cysts in a 13ppm chorine solution, prepare the following: Dissolve 2 grams of granulated chlorine (65%) in 10 liters of fresh water. Once dissolved, add one liter of the solution to 9 liters of fresh water. Once dissolved, add one liter of the solution to 9 liters of fresh water (this will give a 13ppm solution), add one pound of artemia cysts and place strong aeration for one hour. Rinse the cysts thoroughly afterwards and then transfer the cysts to a conical shaped container for hatching.
- Disinfect hatching water: add 2 – 4ppm chorine (0.5 granulated/100 liters = 3.25ppm) to hatching water prior to adding the cysts. This will minimize the bacteria load in the hatching container. The chlorine poses no threat to the live artemia.
- Lower the salinity in the hatching water to 20ppt. This quickens the hatching time as well as changing the bacterial composition in the hatching water. This can be achieved by adding 40% freshwater with 60% seawater. Even a mix of half freshwater with half seawater will give good hatching results.
- Double harvest. The initial harvest can be done after 18 – 20 hours. After this, replace any water removed (freshwater can be used) and return for a second harvest about 6 – 12 hours later. In most cases, one can expect to harvest anywhere for 1 – 10 % of the initial harvest and is especially useful for lower grades of artemia.
- Filter out unwanted cysts. Prepare a 200-micron screen “pre-filter over the container into which the artemia will be harvested. This can be accomplished by attaching a 200-micron screen to a 6” to 10” diameter plastic pipe that has been cut to about 3” to 6” deep. Place this “pre-filter” over the artemia collection container and pass the artemia being harvested through this “pre-filter”. Any unhatched cysts will stay above the screen while the artemia pass on through.
- Disinfect artemia prior to feeding. After the area has been harvested they should always be rinsed and can be disinfected by several methods. A freshwater rinse is sometimes used to eliminate Vibrio bacteria, as most strains of Vibrio do not tolerate freshwater. After a saltwater rinse, 10 – 20ppm of iodine can be added directly to the artemia and after one to three minutes the artemia can be fed to the larvae or rinsed again and then fed.
(Courtesy of GBAqua)