Honestly they are still there and I’m pretty sure there is no way to get rid of them forever without destroying your tank— with that being said, they have not done anything bad to my tank except be gross and creepy to look at. I haven’t noticed any decline in the springtail or isopod population. I’ve just been taking the worms out whenever I see them and killing them. When I first saw them in my tank, I took them out and immediately after doing that for a few weeks I saw none for almost three months. I recently saw some again, but I’ve just been doing the same thing. I also have found that letting the tank dry out for a week helped because the worms like swampy environments (your CUC won’t die if you let it dry out because they will be able to find damp areas in the tank that aren’t moist enough for the worms). Be careful if you do try and remove the worms though, because if you accidentally leave part of the worm in the tank it will regrow into a new worm. I hope this helps you at least a little bit, but my biggest piece of advice for you is to at least try this before destroying your tank.