Do It Yourself DIY Co2 Reactor

Wondering if anyone has tried this?

A more efficient DIY reactor.
Take the gravel tube from a Python water changer (about $7) and connect a 201 powerhead to it ($20) with a short piece of 5/8" hose. To keep fish out of the powerhead, use a Magnum inlet strainer ($3) on the powerhead inlet. At the bottom of the gravel tube, connect an airstone to the CO2 airline. In operation, the powerhead blows water down through the gravel tube. The CO2 bubbles coming from the airstone rise against this current and collect at the top of the tube. When the system is balanced, there is about 1/2" of free CO2 at the top of the tube. Of course, this whole assembly is in the aquarium. The CO2 flow is easy to adjust since you can see the bubbles coming from the airstone.

---------
| |------------------
| 201 | = = = = = | <- Magnum strainer
| |------------------
---------
| |
| |
---- ----
| | <- free CO2
|............|
| o |
| o |
| o | <- Python gravel tube
| o |
| o o |
| o |
| o_ o |
| | |o |
| | | | CO2 in
| | | | I
| I | I
I I
\______________/


The injector seems to be very efficent. Not much CO2 gets away in the form of free bubbles and it can maintain a good level of CO2 in a 150g aquarium (about 15 mg/l).
**For some reason I can't get the image to come out right, so here is a link to the site where I came across this... http://aquaticconcepts.thekrib.com/Co2/index.htm