I have constructed a pond for my bullfrogs exclusively. It seems when I put the newly developed frogs in to the pond from the "nursery" they last a couple of days to a week, then die off. I have lost three this way, and don't want to lose anymore! I tested my pond and the kh (carbonate hardness) is -0. I have live bog plants in the pond and try not to disturb the area much as I heard that bullfrogs prefer murky undisturbed areas. I DO have a pump/aerator installed. Also, should I be supplementing their diet or do you think the mosquitos and bugs that land in the water are enough?