That should do it. There some who say salt helps also, but there's debate about that, and it's definitely harder on your plants (and inverts).
Seems like you caught it early so the Kordon's should be 100% effective. Check the instructions, though, not sure if you're supposed to combine with heat or not.
If your temps are in the mid-to-high 80s you should consider adding an airstone, as water that worm doesn't hold oxygen as well. (only need it while temps are high; yank it back out once all is well again)