Bean Animal overflow problem

My new breeder has a bean animal overflow and I'm having a very minor issue with it. When first starting the secondary pipe starts instead of the main. If I lift the main pipe so it starts the siphon it works perfect and silences down quick. So every time I feed or whatever I have to lift that main pipe up for just a second to restart. I'm wondering if anyone has any ideas. I was going to try adding a short piece of PVC to the main downturned pipe to see if that might start the siphon before the secondary gets a chance.


Like I said, it's just a minor quirk. Other than that the system works great.