That's what Cichlaguapote said, Master.K.
The only bad number is 2.
I was told since I got my baby fish a month ago, that I had to have 4. Now, it'd cost me $30 to get 3 more, and that's more than I can afford, along with the amount of food it's going to take them once they get bigger.
3 total would be much easier for me to purchase and afford to feed. Seeing as I can't have 2, and one is expensive to feed since he won't eat half of what goes in his tank, it'd be better to have more fish to eat the amount that goes in.