I just use an old 2 liter bottle. I have cut holes in a 1/4" piece of plywood to hold 6 inverted 2 liter bottles. I'll try to get a picture of it if you want. I need like 3 or 4 when I am hatching brine shrimp for my clownfish fry.
I decapsulate my brine shrimp. The cysts have a hard outer shell that can be dissolved, but doesn't have to be. Here's how I do it...
1. Dump however many cysts you want into an old soda or water bottle (16 or 20 oz)
2. Rehydrate the brine shrimp cysts. The cyst looks like a deflated basketball because they are so dried out. Fill the container 1/3 or 1/2 full of water (I use RO/DI, but that probably isn't necessary) and soak them for about 60 or 90 minutes. Shake the bottle around every 5 or 10 minutes because the cysts tend to stick to the side of the bottle. This will return them to their normal sphere form.
3. Fill the bottle another 1/3rd full (so add 5ish oz) of regular, unscented bleach. It's usually the cheapest you can find at the store. The bleach will dissolve the outer shell of the cyst. This won't hurt the embryo inside.
4. Shake the bottle a little to make sure the cysts get soaked in the bleach water well. The cysts will turn from brownish black to grey, to a nice orange color. Once they are orange, the shell is dissolved. Depending on how much you add and how strong your bleach is, this can take anywhere from 1-5 minutes.
5. The newly decapsulated cysts need to be rinsed free from the bleach. If you don't do this, it will kill them as they hatch. So, use a coffee filter or any other sieve you can think of to wash them. If you are really patient, you could probably just decant the water after the eggs settle a few times. Decapsulated cysts sink fairly fast. I have found that a 53 micron rotifer sieve works perfectly to rinse the cysts.
6. Keep rinsing the eggs until you can't smell any more bleach on them. You can add some chemical to get rid of the bleach if you want (sodium Thiosulfate?).
7. Add the eggs to your inverted 2 liter bottle and put in the airline. In 24-36 hours, you'll have baby brine shrimp swimming everywhere.
