interceptor is pretty safe, alot safer than treating for planaria etc.. I have treated my tank probably 10 times in the last 3 years without any issues. It will stun the crabs and shrimp and make it easier to get them out. 1- 23mg pill supposedly treated 380g but I usually double the dose. Leave the skimmer going but cut the air off. take out carbon. crush up pill and shake in a container of tank water then pour in display. The stuff doesnt dissolve that easily. 6 hours later you can start skimming etc. With iodine, the red bugs will come off with slime from the acro but wont kill them. Are you sure its red bugs?