How to remove a bulkhead when the threads are stuck tight

[BCOrchidGuy]

You could always try a bulkhead wrench, not sure where you'd get it but they are a narrow flat steel wrench designed for tightening and loosening bulkheads. I'd never seen one before until I got an oceanic reef ready tank and it came with two, one for each size of bulkhead.

Doug

[Bryan]

Use a dremel with the cut off wheel disk to split the bulkhead nut.

[trilinearmipmap]

OK I did the vinegar and water thing and it came off no problem. Thanks.