I decided to make a brine shrimp hatching jar, and post instructions on how to do it. This will take the form (somewhat) of an "instructable" from the "Make" magazine web site:
1.Materials :
1.1.You will need a 2 liter bottle that has held a carbonated beverage. These are a little more heavy duty than bottled water bottles, so they should hold up better. This will probably cost about $2.
1.2.You will need some wood scraps for the base and its legs. The base needs to be at least 4 ½ inches wide (11.5 cm)so it is stable. Wider is fine. It doesn’t need to be a particular shape. Square is fine. Triangular, circular, etc. is all good. The legs need to be at least 1 ½ inches (4 cm) tall to provide clearance for the air hose so it doesn’t kink. You can probably find free materials for this part of the project.
1.3.You will need a length of aquarium air tubing and an aquarium air hose coupling fitting that’s is ordinarily used to connect two short pieces of tubing to make a longer piece. I bought a little kit that contained both of these items for about $2 at an aquarium store.
1.4.(Not pictured here. See picture 8.) You will need an air line “T” connector, and an air valve. I purchased a little kit that had a number of plastic connectors and valves for about $2 at an aquarium store.
1.5.(Not pictured here. See picture 8.) You will need an air line check valve to keep water from flowing from the jar into the air pump. I purchased one from an aquarium store for about $3.
1.6.(Not pictured here. See picture 8.) You will need an aquarium air pump or you can use some air from an existing aquarium setup if you have a little air to spare. I haven’t bought an air pump for a while and don’t know exactly what they cost. You don’t need a very big one. I’d guess under $20.
Actions.:
Remove the membrane lining from the inside of the pop bottle cap if it has one, and drill a hole of a diameter that allows you to fit the air hose coupling very snugly into the pop bottle cap from the outside.
Drill a hole in the wood for the base just slightly larger diameter than the pop bottle cap to allow the pop bottle to rest upside down in the base. For my bottle (Coke Zero, horrible stuff) this was 1 ¼ inches. I didn’t have this size so I bought the bit at a hardware store for about $6.
2. Inserting air hose coupling.
2.1.Insert the coupling into the hole drilled in the pop bottle cap from the outside. It should fit snugly enough that it feels like it might be watertight without step 3.
3.Glue the legs to the base. A wood glue works well for this, but just plain white glue also works fine. Apply a little pressure with C-clamps (or a stack of books) and let the glue set for a couple hours. Then you can proceed to the next step, but handle gently for about 24 hours.
4. Silicone the inside of the cap. Use plenty, but not so much that you plug the coupling. You don’t need to use special silicone for aquariums, but the silicone must be safe for use on food contact surfaces. Check the fine print! I frequently build aquariums and use a lot of silicone, so I buy mine in caulking tubes at a lumberyard for about $3 per tube.
5.Silicone the pop bottle threads. Run a little bead around them and smooth it with your finger. Now put on the cap, nice and tight.
6.Silicone the outside of the cap. Run a bead around it. Smooth it with your finger.
7. Insert the cap into the base. The bottle should stand upright, upside down. Let the silicone cure for about 24 hours.
1.Final setup. Attach the air line to the coupling on the cap underneath the base. Attach the check valve to the air line next. Then attach a small length of air line. Then attach a “T” coupling. Attach a small length of tubing to the part of the couple that is at a right angle to the rest, and attach an air valve to that. Attach a longer airline to the other part of the “T” coupling and attaché the end of the line to your air pump. Cut off the top of the jar. A single edge razor blade or a box cutter knife works well. Fill the jar with one liter of water, and mark the outside with a waterproof (Sharpie) marker. Turn on the air.
Note- The check valve prevents water from flowing into the pump. If no air bubbles up in the jar, the check valve may be in backwards. Reverse it and see if it works. The check valve would not be needed if the air pump was always higher than the level of the top of the water in the jar. But if it is lower than that water will flow into the pump right away when you or a power outage turns the pump off. This can’t be good for the pump! The purpose of the “T” coupling and air valve is to bleed off excess air. You want gentle to moderate bubbling, not an active volcano. Having the valve on a side line allows you to adjust the airflow without creating unnecessary back pressure on the air pump.
Done! If you have followed these steps you have built a hatchery jar. It’s for brine shrimp, but it’s similar to those that have been used to hatch fish eggs for more than 100 years. The fish hatchery jars I’ve worked with use a tube in the center of the jar to deliver water to the bottom, which then upwells and keeps the eggs moving and oxygenated. Yours uses air to do the same for your shrimp.
-Steve Morse
, to do it properly you need small set up. A container, the bigger the better, 4-10L should be OK, I've got three 36 litres plastic rectangular containers. Two of them I'm using for growing shrimps and one to get some resting cysts and for experiments 