You might’ve played with “Sea Monkeys” as a kid, and these were none other than adult brine shrimp (artemia sp.) These tiny crustaceans exist in cyst form until the cysts are rehydrated, upon which, they hatch. Although the adult brine shrimp are not a nutritious food without enrichment, the baby brine shrimp make excellent fish food. Their ability to withstand very low salinities makes them an ideal food for picky fish undergoing hyposalinity treatments.
- Hatching Cone
- Air Pump with Tubing
- Hydrometer or Refractometer (preferred)
- Measuring Cup
- Measuring Spoon
- Sieve (optional)
- 1/2 teaspoon Brine Shrimp Cysts
- 1 quart (4 cups) saltwater (1.018 sg or 25 ppt) with a pH of 8.0 and temp of 80-82° F (26-28° C)
1. Set up the hatching cone. I use the one in the photo from Brine Shrimp Direct (about $35), but you can use an upside down 2-liter bottle (just cut the bottom off). There are also less expensive hatching kits that usually run about $10. The one I use from BSD has a valve for easy cyst separation.
2. Route air line tubing from the air pump down into the bottom of the hatching cone. I use an air line valve to control the air flow (as seen on the right of the photo below.)
3. Add the water to the cone (make sure the valve is closed!) I find it easiest to use 3 cups of reef tank water and just slightly over 1 cup of RO/DI water rather than making saltwater just for this (the salinity should be about 1.018, but check it as your reef tank salinity may be different than mine.)
4. Turn on the air pump. It should not “boil” the water, but it should aerate the water well.
5. Add 1/2 tsp brine shrimp egg cysts. Stir well and make sure the eggs aren’t just floating or sinking. Keep the air adjusted so the cysts stay suspended. You may need to stir the cysts every couple hours for the first 4-6 hours until they are hydrated.
6. Add the light source. Light and water will trigger the hatching mechanism. I prefer to use an easily moveable light as you may want to move the light under the cone after hatching. The baby brine shrimp are attracted to light, so this will help in separation later.
7. Wait. Hatch time will depend on several factors, and it should take 18-36 hours or even longer. Quality eggs will have a higher and faster hatch rate than old, improperly kept eggs.
8. Once the shrimp have hatched, turn off all lights in the room except the light used for hatching. Move that light to the bottom of the cone. Turn off the aeration. The baby brine shrimp will move to the bottom of the cone, and the cysts will float. This separation is important as a fish ingesting the cysts could be injured.
9. After separation, place a sieve (and water container) below the valve. Slowly turn the valve on to begin collecting the shrimp.
10. Rinse the baby brine shrimp in new saltwater or RO/DI water (depending if you want to keep them alive or not during feeding.) The hatching process tends to grow algae and bacteria, and this needs to be removed before feeding.
11. Feed to your tank(s) or refrigerate (usually last 3-4 days). This makes an excellent coral food as well as fish food. Again, these shrimp will survive for quite a while in hyposalinity, which makes treating fish that require live foods (like wrasses, mandarins, etc.) possible.
- I purchase my supplies from BSD. They’re a great company with great products (and I’m getting nothing in return for saying that.)
- Make sure to refrigerate/freeze your brine shrimp cysts. They will last much longer and give you a better result. Keep this in mind during your purchase as many companies keep the cysts at room temperature.
- Do not feed the cysts to fish. This could cause injury or death.
- Make sure you use a check valve with your air pump. Too many people don’t, and this can result in equipment failures…or worse.