Cheryl's 165 Gallon upgrade

[CherylMcKay]

So, I made a change to the plumbing on this tank and I noticed that the bulkhead on the tank was wet on the threads. I don't want to take the chance of the bulkhead failing so I am moving the fish, rock.... Everything but the sand to the 75 gallon. Drain the tank. Replace the bulk heads and build overflows. I am trying to figure which will be best, 2 overflows around the current bulkheads or a large one at the back with the PVC then running to the bulkheads in the centre of the tank? With the second option I think I would run the PVC along the bottom of the tank, then using a 90 degree, run it up the inside back to the bulkhead in the overflow.

I don't know which would be a better way to go?