The natural spawning method I use that has worked well for me
10g tank, full to the top with water- natural planted with soil/dirt substrate and sand cap, 80% of the floor planted with stem plants, 5% rosette plants, 10% moss on driftwood and floating plants that cover 10-15% of the top.
Half full tanks are for the male-not the eggs/fry-if the male is well conditioned and healthy he should not have any problems retrieving eggs during the spawning act. Once eggs are in the nest they should not fall unless they are bad and hopefully he will eat them to prevent spread of fungus to healthy eggs or if the nest is disturbed and healthy eggs can fall.
As the eggs hatch-some may fall, after hatch the healthy wigglers should be able to get themselves back to the nest with occasional help from the father
Eggs hatch at different times in relation to when they had been placed in the nest during spawning. It is common to have different size fry at different stages of growth and development.
An hour or two difference in age can make a big difference in the fish world.
I use lots of common snails-ramshorn, pond, trumpet-they help in the production of infusoria a great live food for the fry, they also clean up any bad eggs and dead fry that fall. I also keep shrimp in the spawning tank. Both the snails and shrimp are part of the natural set-up and have other jobs not related to spawning
I use water that has been steeped in native oak leaves, so the water is a nice amber color
The Betta will use either the floating water lettuce or a sword plant leaf for his nest
I don't add anything artificial in the tank
I keep the water temp at 80F for spawning and fry rearing-I found that at this temp I get hatch within 24-28 hours.
At higher temps my fry hatch too fast and tend to be weaker
I don't use any aeration or filtration
I add both breeders at the same time, the plants in the tank will work as a natural divider to prevent premature egg drops and injury to the female
Spawning will start from a minute to 3 days
Longer than 3 days and I start over
I don't wait on a nest as a sign for breeding readiness, often a male will not make a nest until he has eggs in his mouth
I condition them with live foods, usually mosquito larva, I feed them together in the spawning tank as well and I also feed the male after spawning and during egg/fry care.
I usually remove the female after spawning is completed
I leave half my lights on at night until the fry are free swimming and then I turn them off as usual, my lights are set on a 12 hour photoperiod-due to the plants.
I usually leave the male with the fry the first month or so-this depends on the male and known habits and how important the fry are as well
If the male is a known egg/fry eater I remove him once the fry are free swimming, if he is new and unknown to me I will sometimes leave him and watch unless I really need that clutch of fry.
Males that are know egg/fry eaters are given a chance to change this behavior, if not, they are culled after the third attempt.
I place a plastic veggie wrap over the top of the tank to keep the air above the water warm and humid for the labyrinth organ development
Feeding the fry and water changes
I only use live foods: newly hatch brine shrimp with yolk sac intact for more nutrition, HUFA supplement BBS after they absorb the yolk sac to provide the Betta fry with needed nutrition, white worms-small amounts due to high fat content, and daphnia, infusoria, seed shrimp other micro-critters that are either already growing in the tank for free range feeding or from green water cultured outside in oak leaf/rainwater buckets
You know he fry are eating infusoria and other micro critters in the tank by looking at their stomach-it should be round with little black dots
With NHBBS and supplemented BBS the stomach should look round and pink/orange in color
I start adding the live foods once the fry are about 6-7 days old or 3-4 days after they are free swimming.
Once I start adding the live foods I start making 50% daily water changes.
This is to encourage strong growth and development and dilute the stunting hormone produced by the larger/older fry.
I also will start to condition the fry to a "feeding tap"-I tap on the rim of the tank as I add the live food.
This helps to insure most of the fry are in the feeding area for food, counting and catching/netting when it is time to be moved and most important observation for eating, health, growth and development.
As the fry grow I will start to move the larger fry to other grow-out tanks, usually starting at 6-8 weeks of age
This can vary from one spawn to another, I am not strict with feeding or spawning...I watch the fish and they tell me what they need by their behavior.