I've got some new eggs on order, though I don't really know the quality of either the ones I have or the ones I ordered. I don't know where to get hold of SF bay brand eggs in Australia, if it is even possible.
You'd have to check with local pet shops, or in a pinch, surf over to the SF Bay brand website and ask them if they have a distributor in Australia where you can get their brine shrimp eggs. O.S.I. gets their eggs from a source in Russia and they're also reliable.
I'm also trying with an inverted 2l drink bottle, having read somewhere that the eggs require light in order to hatch. They won't get much light in the black box, though it will be warmer. I wonder which matters more.
Well, artemia don't require light in order to hatch, but they are attracted to light and will swim towards and gather around any light source they can find. In nature, after hatching they swim up towards the light in the salt ponds where they occur, looking for single celled algaes to feast on and oxygen rich water to breathe. Aquarists can take advantage of their light loving behavior by using light to concentrate and collect the little nauplii in their hatcheries. Even shining a flashlight into the brine shrimp container will stimulate the nauplii to swim towards the light, where they can be collected and then fed to your fish.
With the black box hatchery, you'll notice that the cap on the collection bottle is white and the collection bottle itself is clear to allow more light in. From below, the brine shrimps will see the cap glowing with white light if you put it near a light source, which will attract the brine shrimp to the cap. They enter the collection container through a small hole in the cap. I have one of those hatch kits myself and if you do have viable brine shrimp eggs, it's amazing how well it works.
What pH and temperature do you hatch your eggs at? How long do you wait before you harvest the hatched shrimp?
My tap water usually runs about 6.8 to 7.2 on the pH scale depending on the amount of rainfall we've had recently. If you use synthetic sea salt for saltwater tanks, the salt itself contains a lot of calcium carbonate which will buffer up the tap water to about 8.0 on the pH scale. It only takes about a rounded tablespoon of synthetic sea salt to do that. The temperature is whatever my house temperature is at the time. I don't do anything special to warm or cool the hatchery water, just let it sit on a countertop. Hatching usually starts within 24 hours and reaches it's peak at about 48 hours.
What's nice about the black box kit is that the collection chamber is filled with freshwater, which has a different density than the salty seawater. This causes the freshwater in the collection cup to float above the seawater and the two don't mix together, even though there's a little hole in the lid of the collection cup. When the brine shrimp nauplii swim into the collection cup, they enter a freshwater environment and this automatically rinses them free of salt from the black box part of the hatchery.
That makes it extremely convenient to feed your fish with nauplii from the collection cup right away. You don't need a brine shrimp net or have to rinse them off first before feeding them to your fish.
There's also nothing wrong with using the 2 liter soda bottle method for hatching out your shrimp, but it does add the extra steps of collecting the nauplii manually with a flashlight and either a brine shrimp net or a medicine dropper to suck up the shrimp. The brine shrimp will also need to be washed with freshwater to eliminate the salt before you feed them to your fish, but no big deal.
