They eat whatever the bettas don't, mainly frozen blood worms. They also get carrots, zucchini and algae pellets about twice a week.
I have four all up 2 males and 2 females. When I give them a water change ,the tank drops slightly in temperature, the idea is to simulate rainy season.
And like you, I use lots of oxygen.
To spawn in, they only have two small pots I picked up at a two dollar shop.