Six line wrasse or royal gramma to add with single clown?

[neonstingray]

Hey guys,

I have an established 20g with 10g sump and currently the only fish I have is a single clown.  In the 5 years I've had this setup, I've had other fish, but it's always been very aggressive towards other fish.  Even as a juvenile it was too aggressive to mate with another clown.  For the past year it's been alone in the tank partly because it makes taking care of the tank so much easier, but alas having a beautiful rimless ADA tank and sump with only one fish sucks.  I'd like to add another fish (ideally two others and have 3 fish total, but I'll take what I can get haha).  In terms of nano fish that are aggressive enough to possibly add, I've narrowed down to a six line wrasse or royal gramma.  Which do you think would be the better choice considering these requirements?:

1. swimmer and visible

2. brightly colored (for that reef tank fish look)

3. can eat pellets fed once a day and not require careful husbandry

 

Also, I've just moved and setup the tank and rock work from start again, so I can put the new fish first in the tank for a couple days or even a week while I keep my current clown in the temp tank.  I have a mesh top for the tank so not as concerned about jumping.  At this point I'm leaning towards the six line simply because it's supposed to be more of an open swimmer than the gramma.

 

Thanks!

[burtbollinger]

Gramma for sure.  Nothing can touch the pop of color.  

[Clown79]

The 6 line will not be happy in a 20g. 

[seabass]

You might try a more aggressive fish that can stand up to a bully, like a Pseudochromis:  http://www.liveaquaria.com/product/prod_display.cfm?c=15+1500+1116&pcatid=1116

 

Otherwise, I would introduce a small juvenile clownfish of the same species (I'm assuming ocellaris).  Your current clownfish will not see a small juvenile as a threat, and the smaller fish will immediately show submission to her.  Then you should still be able the add another fish (possibly before you introduce your clownfish pair).

[Clown79]

Dottyback definitely can handle an aggressive fish. 

[neonstingray]

Thanks guys, I'll try the dottyback.  I've previously tried to mate this clown when it was younger and was unable to twice, so I'd rather not try that again.

[jesseatam]

There are many species of dottybacks with varying personalities and levels of aggressiveness so do a bunch of research before you pick one.