I've bred and raised hundreds of bettas without too many problems. I always use at least a 5 gal. tank for breeding and never breed in the same tank the betta live in. The breeding tank is first clean thoroughly, never reuse the same water as a previous breeding. Only fill the tank with 4-5" of dechlorinated clean water, adjust the heat so it is stable (betw. 80-82 degrees) and I put in aquarium salt and blackwater extract. No filtering, nothing to disturb the water. Make sure anything you put into the tank is sterile so no bad stuff gets introduced. If you don't have a lid for the tank, stretch plastic food wrap on it to keep the evaporation down, keep the drafts out and keep the temp stable. Make sure the breeders are in completely great health and that you've been doing the high-protein, live or frozen food twice-daily feedings. Make sure there is a halved styrofoam cup or cattapa leaf floating in there so the male has somewhere to build his nest. Put him in when all is ready and give him at least a few days to get used to the big space and to establish his territory, start a nest, overcome his fear. Then put in a clear smaller tank or tube with the female--you want them to be able to see each other but not to be able to touch each other. Let them flare and dance for each other for a day or two while ocntinuing to feed them twice daily. Then release the female but keep a constant vigil (don't go off to school or work or out shopping--you need to be there if things get too ugly). They'll chase around a lot--sometimes for a couple of days (there should be sufficient hiding places for the fish). When the female is ready, she'll begin hanging out under the nest, eventually allowing the male to get close to her. When she's ready to mate, she'll either nudge him (gently) or he'll nudge her and she won't run away. (Don't leave the pair unattended or you could come back to torn up or dead fish, confine the female in her clean tube if you can't be there). If after a couple of days they never reach this point, remove both fish, recondition them and start all over with a clean tank. If the do show signs of wanting each other, they'll soon figure out how to embrace--and this takes practice so be real real patient. She probably won't start releasing eggs for awhile but they will go through the embrace thing. Once she has emptied, she'll move off and look kind of exhausted. She may help pick up eggs and spit them into the bubbles. Remove her and let her rest back in an isolated, clean tank for a few days to recouperate--feed her if she's hungry. The male will pick up the eggs (usually) and spit them into the bubbles and patrol the breeding tank for the next few days, sometimes rearranging the eggs. If the eggs are viable, newborn babies will start hatching between 24-72 hours and dad will try to keep them in the nest. By the third day, most or all of the eggs will have hatched and the babies will be swimming and floating all on their own. Take dad out and into a clean tank for rest and recoup. Babies will live off their egg sac for a couple of days after hatching. If you use live plants in your tank, there will probably be microscopic life the babies will eat but you can put 1 (one) drop of Liqufry in each day if you want. DO NOT OVERFEED because bacteria blooms fast and can kill your babies. Start dropping in vinegar eels (amount depends on how many fry you have) once in the morning and once at night on day 4 after hatching through about day 7. You can continue to drop in vinegar eels but also use microworms (do the early feeding with one, the late feeding with the other). By about day 8-9, you can stop the vinegar eels but continue the microworms, and start feeding newly hatched brine shrimp (but continue also feeding microworms)--only as much as the babies will consume within 5 minutes or you'll pollute your tank and the babies may develop swim bladder problems. They can eat micros and bbs until they get big enough for grindal worms and bigger brine shrimp and daphnia. Then it's just a matter of feeding them food that they can easily get in their mouths and swallow (without choking).
Don't clean the breeding tank until the newborns are about 2 weeks old--during courtship, you can suck out any gunk collecting at the bottom but try to disturb your fish as little as possible. You can add more water at the same temp as the tank water (since you only had 4-5" of water to begin with) if necessary (if it begins to look cloudy) but if it gets REAL cloudy, you will have to start doing water changes, means you've overfed and the bacteria has bloomed. My breeding tanks stay clear for many weeks but I boil all my water and let it cool before using in my tanks and I only start siphoning the gunk on the floor after the babies are 2-3 weeks old. At 3 weeks, I transfer them all to another tank which has been already set up and has had an aged sponge filter going in it for at least a week. At this point, I do a head count. And I just continue to feed them twice daily with food appropriate to their size, start doing weekly cleanings. They grow fast. I have never had any trouble with fungus or bacteria or parasites in my baby tanks (and seldom in my adults). The biggest problem I have is finding new homes for them when they are grown. Hope this helps. You can read up on how to breed and raise bettas in a lot of the know breeder sites.
