Hi. I currently keep my two, two year old turtles in a 20 gallon long. It has gravel, a turtle ramp, a filter, and a light(currently trying to find a UVB light to fit the hood). I want to change the ramp into soil of some kind. I also want to get rid of the gravel because it hides scales,feces,etc. Also, since I got them, one of them had a very small white spot on its top shell. Well that quickly spread to the others, and it hasn't seemed to affect them much, but I also can't get rid of it, even with the betadine flush the vet gave me. Recently, algae has also started growing on their shells, but I have heard that is ok. The white stuff seems to be flaking of on its own finally after 2 years. I don't really know how to word the question but, umm, help?