I have;
Siganus magnificus (He’s likely max size already at 6.5-7”)
Halichoeres chloropterus (Again, he’s likely maxed out at 5” with maybe a bit of growing left)
Pomacanthus navarchus (She has a lot of growing to do at 1”)
Pygoplites diacanthus flavescens (She has growing to do as she’s Atleast 3”)
Chelmon rostratum (He has growing to do as he’s only about 3.5-4”)
Out of all these guys, the ones that aren’t maxed out take years to grow. My CBB was brought at 2” 3-4 years ago and is only now 4”. And I will say, whilst my tank is small with these slow growers it looks rather large.