My mother-in-law and niece got into a betta breeding project. It started out as a school science fair project on genetics for my niece...then grandma got totally into it. We'd visit and they'd have betta cups stacked aallll over every available surface, as well as multiple tanks every where for their keepers and breeding purposes. The babies went into the cups. They were very successful in their breeding. They would sell off the babies to pet stores and even the local Walmart manager would buy some for his fish/pet department. Their babies were always waayyyy prettier and healthier than what the stores would usually bring in from giant wholesale vendors, so they were eager to buy them.
It's been a few years since they retired that project, but I can always check in with my Mom-in-law to ask her for advice if you ever have specific questions you need answers for.