Cleaned and changed the water and re-set up FBT tank last Sunday. I had been doing a partial water change regularly but things were getting a little smelly and without a pump/filter I got busy. The toads had also be turning a dark, almost black, color but I had no idea how instantly the color change would occur once the trio was back into clear, clean water. They went from dark to bright green in a very few minutes. So, lesson learned. And I will add the pump/filter very soon.