My overflow drain has gas

[outtafocus]

By replacing the Rio pump with the less GPH mag7, I feel I have reduced the burping to the point of it being undetectable and the piping entering the sump is at a 45 degree angle. I have also inverted the intake bell on my hoffer gurgle buster and I now have a Stockhoffer gurgle buster standpipe. This have removed all signs of sucking air noise and slurpping.
However the water inside my overflow tower still continues to rise and fall 1 inch. I know this sounds insignificant but it could potentially cause an issue for my auto top off system (Tunze Osmolator) as this rise and fall is felt by my sump.
I have been running a test for the past hour to see what effect this fluctuation has on the Osmolator. So far it seems to be unaffected. I am worried that as soon as I leave it alone for even the shortest amount of time it will want to malfunction.

What is you opinion on this matter?
What do you feel I can do to further reduce the rise and falling?
(the 45 on the drain plumbing is as close to the tank as I could get it, as follows- bulkhead-3" of straight pvc-union-45-8"angled pvc into sump)