As Zack says the issue with keeping anthia in a small volume of water is the amount of waste you will need to deal with, remember anthias will only take food in the water column so any that settles won't be eaten and will rot. You will need a goodly amount of CUC to clean-up. Having said that you may consider setting up a species tank with Ventralis anthias, they like cooler temperatures and more subdued lighting than the 'normal' anthias, so you could set the thermostat lower and have less powerful lights. They are more of a rock or cave dweller so don't need so much swimming space. Tank mates could include Catalina Gobies and Bluehead Jawfish and maybe a Kamohora fang blenny. OK no light loving corals but decorative algae and a gorgonian or two would look stunning.