I just recently set up a 15 gallon tank that is currently in the process of a fishless cycle. My question is when it is done cycling, I would like to add a goldfish, but I'm not sure if I will be able to. I know that goldfish are social fish and usually like more than one, but I have read that you can have 1 goldfish in a 15-20 gallon tank. I currently have the tank set up so that there is plenty of swimming room and I have an AC 30 filter on there (I can add another filter if needed). So would it be possible to put a goldfish in this tank? And if so, which type of goldfish would be best? (For example, I know Orandas grow the largest, so I won't be getting 1 of those) Thanks!