Quote Originally Posted by LJH View Post

I also think that removing them is incorrect. These paddles also help to locate the reel within the tank. A quick check with mine reveals that removing them leaves the reel sloppy in the tank; allowing it to move around within the tank, and possibly causing the sheets to move. By design, the films' stability is highest when the force comes in a radial direction (around the circumference of the reel). If this not centred, the liquids can cause the edges and/or corners of the film to be lifted within their track/groove. With enough non-uniformed radial force (such as would be caused by an out of balance reel moving within the tank whilst agitation/spinning is occurring), I can imagine the film could be fully dislodged from this groove.
Once the lid is on, the funnel will hold down the center core, and the reel will no longer move.

The 4X5 retaining panels are mostly designed to prevent the sheets of rolling off the reel during high speed rotation.
In the past 10 years of using 2509 reels i have never used the panels (older reels did not have them, and as a habit my newer ones dident either...). I have never seen a sheet dislodged in any process i have run, manual or machine.

Inversion is totally possible with the multitank 2, but uses as noted above almost 1.3 Liters of chemistry. If that amount works for you with dilution or stock there is no reason not to do that, and many schools around the world teach that system of processing using the 2520 system tank.