Well.. Its a Cadlights 120 with holes that are very close to each other and the opening under the tank isnt as generious as id like either.. Cant get a wrench on the bulkhead very well . !! LoL. I have dual drains and the one thats leaking is the center drain bulkhead.. Im gonna drain the tank and make the opening under the tank larger then use SCH 100000 fittings hahahaha