Ok so here is my plan..
In my 1500 gallon tank where the bulkheads are I am looking to build a 3 sided partition that is about 2-3 inches above the upper bulkhead and putting it in that far back corner of the tank. Thus making a drain-able sump area for the the 2 bulkheads.
Reason is, right now if the lower bulkhead were to leak I would have to drain the entire tank to repair it. If I put up this partition wall I would be able to work on them dry with only draining a fraction of the water. Problem is I need to install it wet as there are way too many fish in there to do a full drain and the modification.
When I initially completed the tank there was a bulkhead leak and I am not all certain that it won't come back some day. Would rather be safe than sorry on 1500 gallons of water.
So basically this partition wall will be epoxied on all the edges and held into the corner until dried. This partition will also be made of 3/4" plywood and coated with Pond Armor just like the main tank walls.