Too much wrasse for my tank?

[Buddyboy]

Hi All,

I have a Blue Sided Fairy Wrasse (Cirrhilabrus cyanopleura) on hold at a LFS. I did a bit of research this weekend and it looks like their size tops out at 4". I have a soon to be 50G tank. (36"x18") Would this be big enough for this fish? Anybody have any experiences? It's strange because on Live Aquaria the Mystery Wrasse has a minimum tank size of 30G (top size 5") but the Blue Sided Fairy Wrasse has a minimum tank size of 70G! Is there something i'm missing? It's on hold till tonight. What should I do? Thanks for any info!

G