Hi there, although there are many links on the web to teach us how to hatch BBS from eggs, here is a lazy man way with no measurement needed and it works for me
1) You need a 1.5L soda water bottle (I used Pokka green tea bottle as the bottle is harder)with the base removed.
2) add in around 3 teaspoons of salt or fill salt to around the cap area (I used normal cooking salt that I got from the supermarket, $0.20 each pack)
3) Add in tap water (no anti-chlorine added for me because I seldom used that for my fish, if you feel that you need to add, just add in)
4) Add in the BBS eggs
5) Cover the top if you don't want salt water to splash out when you bubble the solution. Start with low "power" bubbling to allow most of the eggs to be soaked in water
(6) Increase the bubbling "power" till you see that there are no dead zone, that is there is no eggs settle at a location
Here is a video of the bubbling "power" to show you roughly how it should look like