When they build bubblenests, it is not always a sign that they are ready to breed. It is kind of confusing I know but most of the time it just means that they are happy and love the life they have. You must be making him very happy to have him build one in a ONE gallon. I have never heard of that before.
In any case, the one gallon cannot be used for a breeding tank. You would need at least a 10 gallon for a breeding tank and a 5 gallon for a quarantine tank for the female to go to after the breeding; and another 5 gallon for the male after he is removed from the breeding tank; and a 55 gallon growth tank for the females; and at least 100+ quart sized (minimum size) containers for the male fry. Those are the minimums for an amateur betta breeding set-up. This does not include all the extra equipment like sponge filters, thermometers, food set-ups for baby brine shrimp and all. It is an expensive and time consuming and very risky business for the fish.
I have a beautiful breeding pair but I will never breed them because of the space, equipment and the level of danger to my fish. I would not be able to be that vigilant and it would be a 24 hour job.
But, again, my congratulations on being such a great betta parent that your little one will build you a nest in a ONE gallon.
Rose
