I have a 20 gallon tank and I did some research into fish I wanted to get but primarily was looking at colors and patterns. I didn’t pay much attention to behaviors. So now i have a clown which is super active and then two fish (green clown goby, and watchmen goby) that never come out. I feel like at most I can get one more fish so I want to make it count. I want something that is active that I can watch swim around. Any suggestions?