fish for 20g

We have a 20g fish only tank. Right now there is a damsel and lawnmower blenny. My hubby wants one more fish for the tank, what is a good fish for this size tank? He likes the maroon clowns, clarkii clowns, etc. I am not sure what he can go with in a 20g. I am used to having to worry about my 55g. Any suggestions?

 

A clown could and would be fine, but they are boring IMO.

What about a firefish, clown goby or a similar small fish

 

I have a royal gramma, a maroon clown and a 6-line wrasse in my 20 high. They all have their own parts of the tank and get along well, all things considered. I'm not sure how aggressive your damsel is though. My clownfish has a pair of anenomes to call home and is content there. Your damsel might not welcome another fish hanging out in the water column.

 

What kind of Damsel is it? Many species of Damsels are very territorial and may become boisterous towards other tank mates IMO>
Your husband may want to get rid of the Damsel and then add to the tank...
There are many small non-aggressive fish available for your husbands tank like a Royal Gramma, Pajama Cardinal, many Blennies and Gobies and small Wrasses(Flasher and Fairy species)!

 

It is an agressive damsel for sure. It's a whitish/ bluish body with a black dorsal fin and yellowe fins on the bottom. I can't remember the name. We tried getting it out but the fish always hides as soon as a net is placed in the tank. It's fine with the blenny but our shrimp died because it always bugged it.