Ok, the 25mm fans didn't do squat. I wish I had seen somewhatshocked's post before I had ordered them
I went to V2.0. It took a while to get it designed and fabricated, but its done and it actually works!
I started with 2 120mm fans. I wanted something what was hidden as much as possible since I would have to use it for months at a time.
I built fan boxes with detachable "chimneys". The boxes are in the stand and the chimneys run up the back of the tank feeding air under the lid.
The material is EVA foam. Its soft and pliable so I didn't have to be exact in sizing. It squishes a bit so it slides behind the tank easily. I also don't have to worry about scratching.
The detachable part is so I can actually take them on and off easily without disturbing the tank.
It fits snugly behind the tank and the top of the chimney raises the back of the lid one inch to provide airflow.
This pic has it at the edge so you can see how it fits. In place it sits about 2 inches away from the edge and isn't visible.
Inside the tank stand the fans side at the sides so don't take up much room. They are silent fans so no additional noise when they are operating.
The fans are controlled with a thermostatic controller so they aren't running all the time.
Of course I had to go for the LED fans just to jazz things up.
Week 4. Tank is cycled and stable. Heat issue is resolved. Time for some fish!