I am currently building a 220 gallon, but I keep catching myself looking at these rimless pico tanks, but I want to know are they really difficult to keep? I know that without the water volume, there is little room for error, but what do you typically use for filtering? Wouldn't most aquarium lights fry corals in a tank that shallow, I know you would have to elevate the light above the tank, but is there a lot of trial and error to figure out how high above the tank? I know it is a lot to ask and there is no one size fits all, but I am interested in peoples experiences.