Ok lets me start by saying that im getting 1 african clawed frog ( a baby, its small) my tank is a 20 gallon and im only gonna house him there , only him. so he has a lot of space to swim arround, my question is.. how deep should the water level be? im worried of him drowning i didnt get it yet im getting it , im getting it tomorrow, also, im gonna clean the tank 1 every week... and add more hides which im buying tomorrow.. the water level is 40cm deep idk... the tank is 80cm long and 30cm wide