I found a solution to my ATO sensor problem. I think this skimmer is going to like having the water level pretty low in the rear chamber, at the level of the skimmer gate at the lowest level. Any higher and the skimmer has the potential to skim the excess water out until the water level drops. This only problem I had with this was the ATO sensor mount is too large to fit between the skimmer and the glass divider but there is plenty of room in the return pump chamber. The old pumps used to sit much higher and there was no room for anything but with the new return pump (sits nice and low) there is plenty of room for the ATO sensor to sit in that chamber. The only other problem to solve was where to put the high water sensor (the one that detects too much water). With the water level low in the back when you turn the return pump off the water level in the back equalizes with the water in the tank. So the water level goes way up in the back. With the tunze ATO sensor mount both sensors are in the same place but the high water sensor needs to be much higher. The solution was already in my tunze box, it comes with an extra mount. So I was able to place the high water sensor next to the skimmer at a higher level. Now everything works great!
Here are some pictures of the new configuration.
Here is where the water sensor is now:
Here is where the high water sensor is:
Picture of both:
Little dusty in there.