Help. Splashing corner drains

Whenever I turn off my return pump (to feed or whatever)....when I turn the return pump back on, the two drain lines pictured above bubble and splash like crazy with air escaping the drains.



Enough bubbles and splash that saltwater has major droplets down the outside of the tank.



I'm thinking of just buying some splash-guards and glue them with silicone in that corner.



Something like this would completely solve my problem but where in the world do you buy stuff like this?







Anyone have other ideas??