Adding a Clownfish to previously mated pair

[helwrj28]

I lost one of my clownfish from a mated pair (I suspect what was becoming female as it was quite a bit larger than the one remaining). I'm curious about adding a second one in hopes of having a new pair... Should I get a bigger one or smaller one?

As a background, I have a 90g system that will soon be fallow as soon as I pull the remaining clownfish out, so both would be in a quarantine tank that I will pretreat.. I have a divider in case aggression becomes a problem.

 

[Funston07]

Get a smaller one of the same type. There will still be possible aggression though, clownfish are mean little fish