I'm so sorry you lost your little ones, so sad
I must be lazy
I don't bother cutting the bottom off the soda bottle and inverting it. All I do is make a hole in the lid a little larger than the air tube so the air can escape, fill with water add marine aquarium salt (if you don't have any then use table salt with a little bicarb soda) add the eggs put the lid back on, feed the tube into the bottle through the hole to almost the bottom. You just have to make sure all the eggs are constantly moving. Sit it on the window behind our tank and harvest them as we need them by disconnecting the airtube from the air pump, leave it sit so the shells separate and float to the top then use the tube to siphon the shrimp out of the bottle and into a very fine net just like I would to do a water change and if you want you can pour the drained water back into the bottle but it's not necessary.
If it's really cold you might want to consider a heat source like sitting it on top of the aquarium lights or something.
I have my baby in an isolation net within a larger tank. Pull him out and into a plastic container to feed an put him back when he's finished. Keeps the BBS out of his home and the larger volume of water means it is much more stable and you don't need to change the water as often
Some pics.
1. One of our hatcheries
2. Where we keep them to hatch them (takes between 12 and 24 hours at the moment)
3. We run both hatcheries AND the axie tank airstone off the same pump using T connectors with the screw in flow adjusters built into them so we can turn off one or turn them up and down as needed. You can just see a white joiner between the tanks
4. This is where the baby lives. he shares his home with 5 baby guppies, 2 Yabbies and 2 freshwater mussels all outside of his little net of course
