OP
OP
FWIW... definitely not just one worm. I put a red light on the tank overnight and checked it with at nest came... found 3 more large worms. I ended up removing all the sand and sifting through it. One of them was at least 12", two others were smaller but still had to go. Hopefully they are all gone now, or at least for years won't be an issue (though to be honest, I never had an issue that I was aware of, other than an inability to keep tridacna clams). I'm a bit worried about how disruptive that was to the mangroves, hopefully they'll bounce back but I had the roots totally exposed (though certainly not dried out) while going through the sand.
