That's fantastic, but I will say I've kept bichirs before, and I would not expect feeder fish to survive with one. While the bichir may not attempt to eat the frog due to it's size, I wouldn't be surprised if an arm got bit every now and then. I still think your taking a risk, but if the frog is fully grown it will most likely not fit in the Bichirs mouth. Bichirs are tropical, I'm not sure what temps ACF's like, but I doubt they overlap. I kept my bichirs at around 78-80.