Six line is the best option, but not guartanteed to work, because they do not always eat what they are supposed to eat.
These guys eat on your LFS especially shrooms, so you need to try to get rid of as many as you can, If you have a turkey baster you can suck out some of those bad boys and put them down the drain. Keep at it and it will start to reduce the population somewhat.
There are some meds out there that some peopple reccomend, but I do not feel the stress to the entire system or the fish from meds is worth it myself.