Sadly, that GDM passed away from what I believe to be metal poisoning from contaminated volcanic based black sand. He went on a 4ish month hunger strike shortly after that post and never came out. After I had an ICP test done and found the STUPID high levels of metals, 2000ųm/l Vanadium and 500ųm/l Nickel, I removed him to a nano I had set up as a make shift frag tank with sand and live rock. He did not try and escape that either. He never regained the strength to eat and shortly after that, he passed away.
That 35g is torn down and empty, I have a 90g SCA cube and a Innovative Marine Abyss 20g peninsula dropoff now, both with a Red Sea screen top. I have a new GDM, that started off in my 20g, but after repeated close calls with my royal gramma at feeding time, the eel has been moved to the 90g. The smallest fish in there is an unswallowable sapphire damsel, so they are all safe. He has still snapped at the damsel. He usually eats every other night, if not every night. If I miss two days of feeding, he tries to catch a fish altho they are all too big to swallow. My past eels have been laid back and usually only ate once a week, not this one... very voracious appetite.
Thats very sad, although I’m glad you were able to catch the issue! 
