When the fry are free swimming for about 3 days, It is a good diea to remove the male. His job is done, and please see the post care for male betta section in the betta breeding page. The fry dont need to be feed for about 1 more day, Live plants are recommended as the inforuisa that is carried by the plants will provide food for the baby bettas. After you remove the male it is important to keep the water very still for 3-5 days. After that day, than it can be ok to turn on the sponge filter on low. Now it would be a good idea to start a brine shrimp culture that is if you didn;t already start the culture. Crushing up betta food untill it is very fine is a good food to use. Very little though.
Growouts. Most people tend to growout their young bettas in larger tanks such as 55 gallons. They are great, as they give the bettas plenty of room to grow and move around. It is a good thing to add extra live plants, as grow tanks tend to get very dirty. Snails and ghost shrimps would be another good item to add to the tank. Another form of growout would be out door ponds. If you live in warm enough areas, you can get some outdoor ponds and grow out your bettas. This is better for some reasons. The direct sunlight will give your bettas brighter colors. Just remember to take some out from time to time to check on their growing progress. In about 2-3 months, it will be time to take the males out and seperate them.
Remember to stock up on jars. When it comes time to seperate the fishes, i always like to seperate some females as well. The reason for this is because their fins will be better than if they get damaged in the grow out tank. The males will have alittle longer fins and start to fight with eachother. At this time, it is time to move them out of the grow out tank and into their jars.