Hello and welcome to FF! Are your frogs African Dwarf Frogs (webbed front feet) or African Clawed Frogs (non-webbed front feet)? Either way you can try to feed thawed out frozen foods like blood worms or live black worms or chopped night crawlers (non dyed from Walmart or local bait shop). Some frogs will take ReptoMin pellets or similar, sized to fit their mouths.

IRT filters, as long as they are not too powerful and create turbulent conditions in tank, it should be OK with frogs and help maintain good water conditions. Good luck !