The venturi-loopback is at the top meaning all CO2 that i feed into the reactor will immediately get sucked up in the venturi and escape as micro-bubbles.
The tiny bubbles are *everywhere* in the aquarium and they have a very slow vertical velocity.

But I don't see so much pearling from plants, sure there are plenty of bubbles under the leaves but I usually have at least a couple of bubble-bands from damaged plants but there are none now.

I know Tom's reactor have the venturi loopback a couple of inches down the reactor chamber so I might be way off? I thought micro bubbles was the way to go so I focused on getting them which I sure have now =)

The pump capacity is 750 l/h and the reactor chamber is about half a litre. The tank volume is 310 litres with a lot of weeds (primarly H. polysperma rosanervig and M. mattogrossense). Dose every other day:
1 cap Seachem Flourish
1 cap Seachem Iron
1.2 tsp KNO3
1/5 tsp KH2PO4
Tapwater should be about 22 ppm Ca 2-3 ppm Mg.
I can see a couple of completely white new shoots on H. polysperma rosanervig and I have quite a lot of Cyanobacteria.

EDIT: About 0.7 watt/l, 2-3 bubbles/sec

EDIT2: I made the reactor yesterday and just recently (last week) changed to a more aggressive micro dosage, and the whiteness seems to dissapear. The Hygrophila next to the reactor have turned to a nice pinkish color in rather short time.

If you want, I can send you an internal to try put if you post it on the Swedish boards. The method I've suggested compared the mist, whether from an internal/external source or from a disc, the disc seems to do the best, but the internal is a very close second.

The disc tosses CO2 mist right into the plants right away, it does not wait as long till a certain volume builds up.

You can toy with the set up and play with the various levels and loops of the venturi itself. My orginal design is unchanged and has been for nearly 10 years.

See if you can find those viewtainers or use those clear packing tubes they sell for poster shipping etc.

You can also play with the tip of the venturi tube and get different bubble sizing.

This also works well with the spray bar method where you fed the excess from the external CO2 reactor out the spray bar of the canister.

Rio also has a special pump design for skimmers that has more impellar blades to chop up air(CO2 for us). I'd like to get a needel wheeled impeller like in some of the skimmers to play with.

I think they would be perfect for replacing the disc as they would add current along with the same bubble mist sizing. Most venturi's do not produce the same size as the disc (evenly anyway) or the mist from impeller fed CO2.

D- I think you can play around with it a bit more and you should hit the signs that you are looking for. Using the entire tank as a CO2 reactor seems like a simple idea, but many have not figured that out just yet.


Regards,
Tom Barr

Many thanks. I will tinker with it a bit more and my Hygrohila is for sure looking a lot healthier. New leaves on the completely white shoots are getting color. I turned up the bubblerate just a tad yesterday and tonight I have some gas buildup, and also a lot more pearling from plants. Looking good so far.

Good, it sounds like you have taken the right path based on the feedback.

I can tell based on plant response whether someone needs to tweak the design/method etc. A little tinkering will go a long way here.

I'm glad you are seeing this for yourself.
Too many folks are skeptical but if the plants pearlk more and also grow more, then we have a definitely good wide ranging observation that is not merely some other gas, or O2 bubbles alone etc.

I'll talk more about that in a few days with the upcoming report.

I may attack lighting soon as I just got my PAR light meter so I can take direct measurements in the tanks.

Regards,
Tom Barr

tom , can you elaborate more on the rio pump you mentioned and how you would set it up. i hooked co2 line to intake of a via aqua 152gph powerhead and it chews up and spitts out very fine mist.then when pump is shut off gas simply burps out to surface.is this anywhere near your idea? along with very good circulation this seems like a simple way to distribute co2. regards,cornhusker