I just had this exchange over email with Stephan Tanner of SwissTropicals.com (quoted with permission):
Originally Posted by FlyingShawn
Are you aware of any data about what sort of flow rates the 16" JetLifter is capable of? I know it would be partially dependent on the strength of the air supply, but I'd probably be dedicating a pump to it (thinking of using a Tetra Whisper 20, but might even go up to one of the two outlets on a Whisper 60).
I'm thinking of connecting the JetLifter to a PVC UGF that would also serve as the intake for a canister filter (Rena XP3). Look at the bottom picture of this post to help you visualize it:
[link to my earlier post]
The concern is that the canister would have such a strong flow rate that it would pull water down the JetLifter instead of them both working together to pull water through the UGF. I'm hoping that the JetLifter is powerful enough to keep this from happening, but if there isn't any flow data I'm not sure there's any way to find out without building and testing it. Even if you don't have any data, I'd appreciate an educated guess!
Originally Posted by Stephan Tanner
The 8" does ~100 gal/h but as you said, that depends on airflow, the taller ones can pump even more.
Now, I would never connect two pumps, airlifters or any other device to the same source (pipe). Hydrodynamics dictates that when flow gets disturbed, the resistance increases several fold; hence if water comes out of a pipe into a T-connector and the flow in both directions is not balanced the resulting turbulence would severely affect both sides. You might lose more net flow than say the lifter might provide, so de facto there would be less going out than before. A canister changes its flow due to clogging over time, so balancing it is almost impossible. I would simply skip the canister, the undergravel is already sufficient for the whole tank.
In other words: the hybrid design is not one of my better ideas.
I still haven't given up on the idea of having a secondary air-based system for aeration and redundancy, but am still brainstorming effective ways to do it (sponges are an obvious option and Stephan suggested a corner HMF
, but I'm not sure I want to take up that much space in my fairly narrow 52gal display tank and that's a topic for another thread).
Going back to my earlier picture of the complete-loop UGF (what Coolnik called a "equalized pressure manifold"), are there any downsides to this setup compared to the original U-shaped design from Liam?