not quite sure if six line wrasses mix well with seahorses but one thing for sure is that mine eliminated my bristleworm population is just a few weeks! Not sure if thats a good thing or not cause brsitleworms arent that bad. Despite the fact that they are somewhat ugly, can eat fish, and sting aquarists, they are good scavengers and will help you munch on the leftover food none of your other tank inhabitants can reach.