I have a 36"x24"x22" inch aquarium with sump, which gives about 300 litres of water in total. But, it is the amount of swimming space that I think is critical. My Halichoeres wrasse have all been on the smaller side which has been ideal. Some of the species I have looked at would, I now think have been too big.
A second species that I came very close to getting was H. melasmapomus, the Earmuff wrasse. A stunning species, pink but with lots of highlights. Again I was very fortunate as I saw a Macropharyngodon kuiteri. Wow, a beautiful fish that I had never seen before. Similar colouring to the earmuff but smaller. I know the Leopard wrasse are ideal fish in my little reef, so once again a good choice.
Two other species that have worked well in my little reef have been H chrysus and H. iridis. Again they are on the smaller side for this genus and are also peaceful fish that don't bother anybody. The smaller Halichores species are pretty much reef safe but mine, I think may have been responsible for the disappearance of some smaller hermits. The bigger the fish the bigger the prey they can handle.