If at all possible add a heater to the hatchery. they hatch better and faster in the mid 80's then at room temperature.
Straining BBS isn't as easy as just using a net. You need to wait until things settle out as unhatched cycsts will fall to the bottom and empty shells will float to the top. The BBS will basically stay in the middle of the hatchery. They are attracked to light so you can use a fine beam of light on the side of the hatchery to attract the BBS to a place you can syphon them off. It's not exactly the easiest thing in the world to syphon but it works.
if you want to keep them alive for a few days photoplankton is the best food source however powderized spurulina is also accepted. feed VERY LITTLE or you will have problems with poluted water.
Hatch usually takes 24 hours - maybe a bit more. Turn off the air and let it all settle a few minutes, if you see alot of swimmers they are ready. I'm sure you didn't decap.. so you should have alot of debris floating and sinking.. if you dip in a net you will catch a bunch of debris.
If you have airline running through the cap.... wait for all to settle then allow a little water to drain through the airline into a waste container to get rid of the debris on the bottom, then run the rest through a brine shrimp net (or coffee filter) stopping a little before the bottle is empty so you don't get the floating stuff. At this point gently rinse the bbs under running freshwater to remove bacteria or other nasties. Then invert the net into a container of new saltwater. HTH
Okay, I checked this morning. Alot of crap on top!! At first, I thought it was a bad batch of eggs. But after a bit holding the bottle up to the sun, I could see a boatload of those little guys swimming around.
So, after work, I will rinse them and see if Mike is ready to "catch that tang"!
for whats its worth I don't rince them I just move the light lower and they all swim to the bottom, then I skim the junk off the top (egg shells) and I dump the rest strait into the tank. the other way is to put the light at the bottom so all the BBS swim to the bottom, then use a turkey baster to suck them off the bottom.
if you are doing them for food, harvest after 18 hours.. newly hatched are the most nutritious.
They are not capable of eating for about 24 hours after they hatch. I'm guessing they would live for several days before they would actually die. But it's true that they are most nutritious right after they hatch... after the first 24 hours they are really only a package that holds whatever you have fed them. They are filter feeders and eat anything that their feet catch that is under 50 microns in size - I recommend phyto live or not.