All sponges, including the Halichora Species will require some very special care to survive in the home aquarium. The most critical concern is that it never be exposed to the air. If it is, air becomes trapped in the matrix of channels that line the inside of its body. With air blocking the path for planktonic food to reach its cells, it will basically starve.
The Blue / Purple Sponge will require supplemental feeding with liquid plankton and other dissolved organic foods.