For years, I used a classic DIY brine shrimp (bbs) hatchery design that worked fairly well; the simple design employed a couple of 2L plastic soda bottles, some rigid airline tubing and a desk lamp for heat. The main problem with this rig was that the upside down bottles were top-heavy and could tip over easily. From that first design, I eventually moved up to a couple of “professional” brine shrimp hatcheries purchased from Aquatic Ecosystems and Brine Shrimp Direct. These hatcheries are surprisingly expensive for what you get, and I also found that the plastic cone cracked easily with normal use, and the entire device was then unusable. The Pro series hatchery was made of a cone shaped piece of plastic in a stable stand, and with a spigot for easy separation of the hatched shrimp from the floating shells. These hatcheries worked fairly well in a warm indoor environment, but when I transitioned to an unheated garage, I was struggling to hatch large enough quantities of bbs to feed my winter and spring spawns. The main problem was that the desk lamp did not provide sufficient heat to hatch the cysts within a 24 hour period, but there was no way to insert an aquarium heater into the hatchery, or to submerge the hatchery and stand into a heated aquarium. It was really essential that I could reliably hatch bbs in 24 hours or less, since I am only able to visit the fishroom once a day, and I need to be certain that there will be a daily supply of this indispensable live food. Aside from the temperature challenges, I would also occasionally find that the hatch failed because the airline became clogged with salt and brine shrimp cysts, which was just as frustrating. So this year, I decided to go about re-engineering the brine shrimp hatchery to overcome these problems.
I knew that I needed to enclose the hatchery in a heated environment, so I began with a 10 gallon aquarium, a 50 Watt submersible heater, and a glass cover. Since the cone shaped hatchery and stand would not fit within the aquarium, I began to look around for another container that I could use. I thought a large glass pickle jar could work, but I was unable to find one. Eventually, I stumbled across an old plastic iced tea pitcher that had some useful features. The basic shape of the pitcher was a tall cylinder and it had volume markings on the side.
The plastic was clear, and the bottom of the pitcher was flat and stable. It also had a lid with a hole in the center. The hole is designed for a press that would hold down the tea bags, but it was a convenient entry port for the airline tubing; of course, any lid could be drilled to accommodate the airline. I filled the pitcher with water to the 1.5 L mark and placed it into the aquarium, I then added water to the aquarium just up to the level where the plastic pitcher began to become buoyant. Typically, brine shrimp hatcheries have rounded bottoms so that the cysts will remain in constant motion and not settle to one side or the other, but this shape creates more problems than it solves. A rounded bottom requires a stand so that the unit will be stable. I tried the setup with the flat bottomed pitcher and just a piece of flexible tubing, and found that even a small Whisper air pump provided enough airflow to keep the cysts from settling, so this eliminated the need for a rounded bottom, or a stand. In my experience, I have found that the thermostat calibration on common aquarium heaters is unreliable, particularly when the ambient temperature is below normal room temperature (as in a garage). I happened to have a separate temperature controller that is very accurate, so I plugged the aquarium heater into this, and set the temperature for 84 degrees F. I tried out the new set up, and found that I was now able to hatch bbs, in less than 24 hours with a room temperature of only about 55-60 degrees F. When I was ready to harvest the bbs, I simply poured the pitcher contents into my old conical hatchery, and used the spigot to harvest the bbs from the bottom.
After a couple of successful runs, I once again experienced a clogged airline, and a failed hatch. Since it appeared that the salt had crystallized inside the rigid airline tubing, I removed the rigid piece and only used the flexible tubing since the inner diameter is wider. I also assumed that the recommended salt concentration provided with the brine shrimp cysts produced a super-saturated solution, so I tried reducing the amount of salt and saw no reduction in the hatch rate. I currently use 1 rounded Tablespoon of rock salt and a half teaspoon of baking soda per 1.5 Liter hatch (about a half teaspoon of cysts), and I haven’t had any more problems with the clogged airline.
And finally, after I collect the bbs in a small plastic cup, I then pour the cup of bbs into a rectangular plastic container with fresh water and a pinch of salt. I do this step to separate the shrimp from the remaining unhatched eggs and shells, and to avoid pouring the ammonia-laden hatching water directly into the aquarium with the fry. I use a handheld LED work light to attract and concentrate the shrimp to one end of the container, where the cleaned bbs can be sucked out with a turkey baster and fed to baby fish.
One sad note that I must add… I recently learned that young goldfish fry can actually die from overeating of bbs. I was already aware that this could happen with powdered and granular fry foods, but in fact they can rupture their guts on bbs alone. It is better to feed multiple times daily if possible, and don’t add more shrimp than they can consume in about an hour at a time. If you notice extremely distended orange bellies, you should back off the brine shrimp feedings until they are looking normal again. It seems that steamed egg is a safe supplementary food that they will pick at slowly without overeating.