The tank would be in my room-the cat goes in the room, but never onto the desk, bedside table, or dresser. The best location for the fish may be on my dresser-I was going to use my desk or bedside table because they get more natural light, but if I used LED lights that wouldn't be a problem, right? I have a different cupboard that gets more light and is higher, but it is nearer the bed and the cat could potentially jump from bed to dresser. It would also be too high for me to clean the tank. Bedside table has easy cat access from bed-and desk is easily jumped on. However, cat knows that he is not allowed on tables of any sort, and I've never seen him get on my desk.
If you use an LED light for the tank, you won't need any natural light. You could put the tank on your dresser.