My experience is that in long terms, it's better to buy a tank specifically for BB guppy, a 20cm cube tank would cost you just HK$35-40 only. They will grow better, bigger and faster in a relatively bigger environment before elimination (if you choose to do so). Add some moss for them to swim around. Feed them with anything you like as long as the food is clean. I suggest mixing with hi-calcium ingredients for bone growth. Anyway, if you really want to breed, be prepared to separate the male and female for keeping after one month. Some experts even choose to raise the babies always under lights and using heater to keep the temperature pretty high (around 28C) as they would grow faster because the first three months determine their adult sizes (the bigger the better). The shortcoming is that their lives may be shorter than usual.
I hope this helps. Good luck!!!
