I have a gallon bowel on my dining room table with sand, moss, yellow shrimp, no filter or heater. The light above the table has 5 13 watt CFL bulbs it sits about 3 feet above the table and is only on when I need it to be, maybe an hour a day. I do not allow any sun light to hit the bowl, no water movement and sun light is a breeding ground for algae. I do a 90% water change once a week. To answer your questions you can use any substrate you want, carbon is not necessary unless you are trying to remove medication, changing the water should be based on what you have in there and how long it takes to get dirty, inhabitants should be something that has a small bio load and is comfortable with being in a small tank, stay away from the sun if you can.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.