Yes, it is the same valve. I have been using a 5074 for about 18 months now on my tank, I have the older duckbill check valve and it still works fine. It is identical to the Tetra one you linked to and I get no great reduction in flow. Unfortunately they just don't make check valves for water in such a small size. We switched to the spring unit because it created less restriction and the material doesn't harden and fail over time. I can only guess the last batch of these check valves must be flawed, I will try to contact the factory next week for an answer as well as trying one myself. I would be curious though if zip tying the line up a bit higher wouldn't solve this as the check valve is really not the main back flow preventer it is looping the line up. On mine the line is looped up about 1" above the actual vessel, the line is tied to the other line.