Clownfish Aggression?

I'm picking up a second ocellaris and I'm wondering where to put him.   I have a 6 gal nano which currently has one ocellaris who has been there 5+ years and a small cuc. Over the years he has had 2 different tankmates. Originally, he was with a blue & yellow damsel for maybe a year and then a black clown goby for about 4 years. The goby went to the big fish tank in the sky 6 months ago. Mr. Clown never showed any aggression towards either tankmate. Should I be worried about adding a smaller clown?

The other option is to put the new fish into a 20 gal pseudo-reef that I have in my basement. Originally, it was a rock curing/seeding tank, but now I'm 3 months in and it has a couple of softies and a cuc all of which are doing great.

The only reason I prefer the nano is because then I'll see him daily, but if it's life or death, the basement tank will work until my 65 gal is ready.

What would you do?


Edited by superman1981 - September 06 2016 at 3:01pm

you can put it in a clear box inside the 6 and see if any aggression comes from the established tank mate. If yes, then downstairs, if no, then try it.

Great advice Mark & Phys. I'll have to try the container trick and see how it works out.