You can brush your back regularly, but it is recommended not to use a toothbrush. The bristles of the toothbrush are too hard, which will damage the turtle's back. There are protective layers and growth lines on the turtle's back, which will affect its appearance if it is brushed off. I tried to raise shrimp, but it didn't work. Shrimp has a limited food intake and is eaten by predators, which has little cleaning effect. So generally speaking, brush the back with a soft brush to keep the water in the tank clean and prevent the growth of green algae, and you can also add a filter screen. But the green crocodile looks good ~