I have a 4 x 6 horse drinking trough which I use outside for my torts to enjoy some water. It is half water and half sphagnum moss and dirt. My 2 leopards enjoy the water when they are in it. I also have 2 stars , one is 1 year old the other about 4 months. Will I need to change the moss and dirt due to poop and urine if I used it for the stars? I will be changing the water each time.