I have three leopard geckos thought two be two females and a male, but not im sure i have three females. in the last two weeks ive noticed the consistency of their waste has changed to almost look like diarhea. Is this something to worry about , what are your guys thoughts. Its a 20 gallon high, 75 watt heat bulb, and a heat mat. has a humid along with driftwood. I have them on vita sand now but they were just placed on it this week so thats not the issue. the three geckos are about 6"-7" total length and weigh in about 35-40 grams each.