Plumbing/Siphon/Water Disaster Avoidance Advice

[Der_Iron_Chef]

I'm working on the group home aquarium set-up (yeah!), and I want to plumb a return line (from the sump) that enters near the bottom of the aquarium. Obviously, were the power to go out, it could create a siphon and empty almost the entire contents of the tank out into the sump, onto the floor, etc.

I'm hoping to avoid this!

So, if I had a return line placed like so:


Could I frankenstein it like this....and would it prevent a siphon?


Thanks in advance