Dino outbreak in frag tank?

I setup my frag tank plumbed into my main system about 3 months ago. The whole time I've struggled with dino outbreaks. There doesn't appear to be any in my display tank at all though. The skimmer outlet powers the frag tank I'm wondering if somehow that is the issue?



I have tons of flow in the tank but every few days I have to pretty much siphon out the tank because it's so full of dinos.