Well, I finally got the big tank back and finished reinforcing the crossbraces.
I don't think that they will seperate again. I also had the tank drilled for internal overflows. Here is how they look.
I had four holes drilled and will be using three bulkheads for overflow and the fourth for a tank return. If I decide I want a bigger pump later, I'll use all four for overflow and set up a manifold return.
Hopefully by the time the weekend is over the big tank will be up and running again.