Let me start off by saying that, there are more than one way of setting up a breeding tank for bettas.
I've seen all sorts of breeding setups that work in farms and in fish keeper's home. Over the years, I've tried many different setups and found that I have high success rate high (approximately 80%) getting bettas to spawn with this setup.
Tank Selection
My preferred tank size is as follows:
Dimensions: 26cm (H) x 39cm (W) x 24cm (D) with a lid
Here are the reasons that I use this tank size:
The tank is big enough for the female to swim away from the male if she's getting harressed too much and she's not ready, but small enough such that the male is always able to see the female.
The depth of the tank allows water to be added after the eggs have hatched, hence increasing the water volume so that the water conditions are more stable.
The lid keeps away draft that breaks up the bubble nest as well as affected fry labyrinth organ development between three to six weeks after hatching.
Covering the tank's sides
I like to cover 3 sides of the tank, leaving only the side that will be used for viewing the inhabitants. I usually use laminated white A4 size copy paper for the sides and laminated A4 size coloured paper for the bottom. The reasons of doing this are:
Giving the breeding pair a sense of privacy and assurance.
Keep any distractions (moving fish in neighbouring tanks) to a minimum.
Facilitate spotting of eggs and/or fry, remember, betta eggs and fry are tiny, spotting them with a reflective background can be difficult.
Location for Setting up the Tank
Here are some considerations for where to setup the tank:
A place where the temperature doesn't fluctuate too much.
Human traffic is minimal.
Little to no draft.
Water
Bettas can tolerate a wide range of water condition, but prefer a slightly acidic water (pH 6.5 to 6.8 for Splendens) with temperature between 25 to 27 degrees celsius.
I usually mix 70% rainwater to 30% dechlorinated tap water, with a squirt of Indian Almond Leave (IAL) extract.
There are many reasons (I won't go into those) why it is recommended to add IAL extract to water for keeping bettas. For breeding, the main purpose is that it helps stop the bubble nest from breaking up.
Water Level
I tend to set the water level at around 9 to 10 cm deep, with the container that holds the female 1 to 2 cm taller and filled almost to the brim. If the female has been well conditioned and is keen to spawn, she'll jump out of her container on her own. I find that chances of spawning are almost 100% if the female jumps out on her own rather than being released manually.
Where to Build the Bubble Nest
This doesn't always work, but it usually does. I remove bubble nests from other tanks and place it at a spot that is easy for me to monitor if there are any eggs/hatched fry, usually at the front of the tank. When the pair of bettas are added to the tank, the male tend to build up on the bubble nest that is already there rather than on another spot.
Scoop up some bubble nest using a spoon, it doesn't have to be from the betta that you're trying to breed.
Place it where it would be most convenient for you to monitor if there are any eggs.
Day 0 - 18:00: After the tank is setup and the seeded with some bubble nest, place the female into the container and the male in the main tank.
Day 1 - 06:30: As expected, a well conditioned male wastes no time building a bubble nest at the spot where there are already some bubble nest.
Day 1 - 20:00: Long day at work, came home to find the female had already jumped out of her container to be with the male.
Spawning
Day 3 - 13:50: Came home from weekend groceries shopping, just in time to see the male wrapping around the female.
Male picking up the eggs that the female has dropped.
Well, that didn't seem so hard was it?
As I mentioned at the very start of this post, there are many ways you can setup breeding tank for bettas, it's just a matter of finding what works for you and fine tuning the process and finer details so that you get good results each time.
Happy fish keeping!
Jeff "AquaGeek" Ong