Let us examine what brine shrimp are, where they are found and harvested.
Brine shrimp are naturally found in lakes that are of very high salt content like the Great Salt Lake in Utah. Most of the adult brine shrimp sold as frozen shrimp or packaged as eggs are harvested there. San Francisco also harvests a similar specie of shrimp but in my experience they are of a smaller type. This article will refer to the eggs obtained from the Great Salt Lake.
There are several methods to hatching brine shrimp, too many to cover them all. I will explain the method I have been using for many years. You can easily adapt the container size or amount of containers for your particular need. Many fish breeders use one gallon pickle jars or cones that are made from glass or Plexiglas. I have been using 2 liter plastic soda bottles for several years now and find them to be easiest. Soda bottles are correctly shaped for shrimp hatching when turned upside down. This creates a funnel or cone shape that helps keep the hatching eggs in constant motion. Cutting of the bottom of the soda bottle is necessary for ease of cleaning. As you can see from the photo I use the plastic carton from the 2 liter soda bottles as a holder for my hatching containers. If smaller or larger bottles are to be used you will need to either make a base or construct a holder to keep the bottles stationary. I also use airline pipe valves drilled into the bottle caps for my air supply. If you decide to use this method make sure to place air line check valves below the containers to avoid draining the container if the air supply is stopped. You can also use rigid tubing attached to your airline and weighted down or clipped to the soda bottle to keep it in place. DO NOT use an air stone to aerate the water as it will create a heavy foam.
So we now have our hatching containers and air supply .A good quality brine shrimp net is also needed. Most better pet shops carry them. What could be added is a light source that is kept near the containers at all times. This will help in the hatching time and will also assist in separating the live shrimp from the spent shells when hatching is completed. Hatching times will vary due to the temperature of the hatch and the quality or source of the eggs. I have learned never to purchase eggs from the local pet shops as these eggs have probably been on the shelf for some time. Mail order suppliers are a good source for purchasing eggs and some brands are better then others. Over the past few years due to world wide use of Utah eggs, El Nino, poor harvests or just plain poor harvesting has plagued the tropical fish industry. Prices have risen, fallen and today have risen again. All in all baby brine shrimp is still the best source for high quality fish food for livebearer fry and juveniles. Few show specimens are ever raised without being fed live baby brine as a first food.
There are several recipes for preparing the hatching solution. I will discuss some of the older formulas first. Kosher salt or non-iodized salt is used at the rate of 4 tablespoons per gallon of water. A ½ teaspoon of either Borax or baking soda is also added to help soften the egg shells. What is important is that a specific gravity between 1.020 -1.025. Although lower gravity works, better hatches are obtained in this range. I have been using sea salt by itself for several years and the hatches are very good. It may be a bit more of an expense for the sea salt but the hatches remain very consistent. Adding some PH Up or baking soda will also increase your hatch. For a two liter bottle filled a little more then ¾ with water I use between 1 ½ – 2 tablespoons of sea salt. I do not add the shrimp eggs until all the salt is completely dissolved. The amount of tanks and or fish will determine how much brine shrimp eggs you will use in each container. I suggest no more then ¼ teaspoon for a small setup and 1 -2 teaspoons for 50 tanks or more. If you cannot use all the shrimp when hatched I suggest placing the unused portion in the refrigerator to be used later that same day. Baby brine shrimp is best fed to your fish about ½ hour to one hour after feeding dried food. The reason is that the dried food will still be in the fishes digestive system and the shrimp when fed will not become digested too quickly. I have no actual proof of this happening but the bellies of my fry seem fuller when fed this way.
Hatching time varies as I have said due to egg quality but temperature will play an important role in hatching time and hatch size. I try to maintain my hatching containers at about 80 degrees which gives me a good hatch between 24 to 36 hours. This is something you will need to experiment with. When you feel the hatch is ready you can either remove or shut of the air supply. I pour my hatch (I use two 2 liter bottles) into a large glass pickle jar which I keep slightly tilted on one side. Allow the hatch to sit for about ten minutes. All the hatched shrimp will collect near the bottom of the jar. If the light source is situated near the jar or container the shrimp will become attracted to the light and will make their removal easier. I use a siphon hose slightly larger then normal air tubing to remove the shrimp. I fill the hose with water and place my finger at one end keeping it lower then the container as I insert the other end into the container. Once the end is at the bottom of the container I release my finger and drain the shrimp into a plastic container. Make sure you stop the siphon before the container is emptied to avoid draining the spent egg shells. I then pour the shrimp into my shrimp net. It is important to rinse the shrimp while in the net under cool fresh water. Next you will turn the net over and with the aid of some running water rinse the net again so the shrimp wash off and are collected into a small container. There are several methods to fed the shrimp but using a turkey baster makes the job quick and easy. Another way to fed the shrimp is by using a mustard type squeeze bottle. I have found semi-clear bottles to be easier than the old turkey baster. After feeding all your fish, babies first, rinse everything off and allow to dry until the next use.