So I was wanting to do a smaller SW reef tank say 30g at the most with several small reef safe fish! I loved several gobys that I saw on live aquaria and they all were rated as easy/beginner fish that were peacefull! however when I was experimenting with AQ advisor they said that different gobys should not be kept together or they may fight aggresivly! So are they agressive towards each other or would it be ok to keep a few together???