Installed bulkheads for coast to coast overflow. Filling to right below window to see if leak is evident before water reaches the window. I don't think that the window is the issue. Just using it as a test mark.
I do have an idea for testing for the minute possibility that the front window is the source of the leak. I plan to cut a piece of pond liner to cover the window then secure it with a 1x4 frame behind it then coat over the screws with Permadri or maybe just silicone and let dry for 24 hours.
Not leaking this morning. Kind of embarrassing that the leak is not below the window. What I did to the bottom won't hurt by any means, but seems unnecessary now. Going to raise the water level a couple inches when I get home.
Went home at lunch and found that the floor is damp on the back side of the tank. I didn't have time to inspect it thoroughly. Will do when I get home.