When your tank leaks all the way into a 500 gallon tub, then post in the big tank forum.
And if you read what you posted and can actually figure out what that means, then you have a better imagination than me. No photos, no description, just telling us plumbing is leaking?
How about this, "I tell you I crashed my car into a wall, The car doesn't start, I put some gas in. Which parts should I get at the auto part store?"
Reef Aquariums are complex things. And everyone plumbs there tank differently. No body here has any idea what your plumbing is.... Bulkheads, threads, adapters, unions, valves, check valves.... There are so many pieces of plumbing under a reef tank. No body can tell you what to fix just because you tell us it's leaking.
Good luck