nolapete;4483815; said:
I have an idea and want to see what you guys think.
Build a 2x4 frame
Cut a piece of liner to cover the acrylic (I have a section of old liner that may be big enough from one that had holes in it)
Secure the liner over the acrylic to seal it off from the rest of the tank
Test fill to see if it's the window seal causing the problem or not
I think that is a great idea. Once you can exclude the rest of the tank from being the culprit, then you can concentrate on fixing the window.
My 3000 gallon outdoor tank had leaks initially too; I did the same as you: drain, inspect, re-coat, refill, repeat. My windows were the main culprit. It still has minor leaks on and off (around some windows), but its outside so it doesnt matter.
Since your tank is in the house, I know you cant settle for ANY leaking, so I feel your pain.
Hang in there.... your close. Those extra coats were a good idea anyway.
Congrats on the engagement too!