Finally had time to put up the visquene and boards. About to go turn on the hose and start the test. I don't know what the result is, but I have a plan for either result. 2x6 frame over the plywood/rubber gasket joint on the window if it's the window. Liner if it's the tank.
I guess with that plastic and tacked on wooden slats your hoping to prove either way where the leak is coming from, provided the plastic which I am assuming is sealed with sealer on both sides, will hold out the water temporarily for this test. I certainly am hoping so and that any solution decided upon works well and permanently.:grinyes:
By the way, what is that thing below inside the tank that looks like the corner of a coffee table with a cup holder built in , not an underwater coffee table?