I first noticed the redness maybe 2 months ago. At that time, I changed the substrate and disinfected the tank as best I could. Now a month and half later the redness is the same or maybe worse. The frog has been underground that whole time so he is not defecating or urinating so the substrate is not getting dirty. I am not sure how much cleaner I can get it. I gave him a soak yesterday when I took those pictures.