Dude... I have no idea how many times do we have to say to not keep pacman frogs together. no idea how many times will we need to say that. Can you imagine how many dangers are there in keeping like that other then plain cannibalism. I'm getting mad now....

Oh and if you keep your frogs clean gnats wont be there. Clean and disinfect your tank completely with full substrate changes every 4 weeks and change water every day.