# CO2 Diffuser or Reactor or Both?



## magicmagni (Aug 19, 2004)

So what is the "best" way in your opinion to diffuse Co2 into a planted tank? Lets assume we are working with 3WPG on up if it matters.


Co2 diffuser?

Co2 Reactor?

Both?


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## banderbe (Nov 17, 2005)

There's already a poll about this in the APC Polls forum.

http://www.aquaticplantcentral.com/forumapc/apc-polls/14588-how-do-you-diffuse-co2.html


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## magicmagni (Aug 19, 2004)

Oh thanks for posting the link. I guess the mods can delete this one...


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## hoppycalif (Apr 7, 2005)

There is no best way, in any case. It depends on what you like best, how it fits in with the rest of your equipment, whether you mind "wasting" CO2, if you enjoy having a tank full of fine CO2 bubbles, if you need a powerhead for extra circulation or not, and probably other criteria I can't think of. The goal is to get 30-40 ppm of CO2 dissolved into the water - how we do that isn't important.


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## magicmagni (Aug 19, 2004)

That's one side of the coin, but the other is that the pure Co2 bubbles blowing around the tank to get direct contact with the plants is more effective? I'm really on the fence here but then I see some of those Amano tanks everytime I go into aquaforest and they are quite nice and I notice all he uses is diffusers. Why does this appear to work so well? Maybe there is something to bubble mist? Hard to say. I am getting decent results with my in-line reactor, but if I can get better growth with something else I want to look into it.


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## hoppycalif (Apr 7, 2005)

I use the mist method and it does work better, in my opinion, judging by the effect on pearling. But, I know some people don't like the appearance of the bubbles in the water. So, I still believe that the main objective is to get the 30-40 ppm of CO2 disolved into the water.


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## banderbe (Nov 17, 2005)

hoppycalif said:


> I use the mist method and it does work better, in my opinion, judging by the effect on pearling. But, I know some people don't like the appearance of the bubbles in the water. So, I still believe that the main objective is to get the 30-40 ppm of CO2 disolved into the water.


How do you differentiate between pearling and CO2 bubbles collecting on your plants?


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## hoppycalif (Apr 7, 2005)

CO2 bubbles don't collect in any great number on my plants, and those that do are very small. But, pearling makes ever larger bubbles, which finally let go of the plant and go flying up. Also, the CO2 bubbles collect mostly in the direct path of the powerhead output, while I get pearling from every plant, varying a lot by species. Of course, one problem with observations is that you tend to see what you are looking for, so I can't say for sure that one bubble is CO2 and another is O2. Once I get rid of my GDA, assuming that glorious day is actually coming, I will be able to watch much more closely what is happening. (And, I will have much more incentive to be more careful with CO2 concentration and fertilizing more accurately.)


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## Ibn (Oct 20, 2004)

Definitely not both after having tried it. Cleaning out the diffuser in the reactor gets boring; grows plants amazingly well though. :lol:


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## magicmagni (Aug 19, 2004)

Thanks for chiming in folks. I really appreciate you sharing your observations hoppycalif and your skepticism banderbe. Ibn: ya cleaning it all the time is something I have to list as a negative here although I don't mean to put my diffuser inside the reactor as you did so I'm thinking that maybe just having to clean it once a month.

I'm thinking of just installing a "T" on the Co2 line. One side would go into the reactor and the other would go to the diffuser that would be placed under the stray bar, which is directed downward.


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## banderbe (Nov 17, 2005)

magicmagni said:


> Thanks for chiming in folks. I really appreciate you sharing your observations hoppycalif and your skepticism banderbe. Ibn: ya cleaning it all the time is something I have to list as a negative here although I don't mean to put my diffuser inside the reactor as you did so I'm thinking that maybe just having to clean it once a month.
> 
> I'm thinking of just installing a "T" on the Co2 line. One side would go into the reactor and the other would go to the diffuser that would be placed under the stray bar, which is directed downward.


I believe the CO2 will simply follow the path of least resistance, so one of your devices won't get much if any CO2.


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## magicmagni (Aug 19, 2004)

Yeah you are correct. Not sure how I'd deal with that. Perhaps install an in-line valve -not sure. Another thing I was thinking was to drill a small hole in the reactor a few inches from the top and run an air hose from there to a small pump or powerhead inside the tank. The venturi action of the pump could suck the gas out of the reactor and spit if out as micro bubbles throughout the tank.


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## banderbe (Nov 17, 2005)

I think there is a device to allow multiple tanks to get CO2 from one source.. I think it could be used in your application.. look around, I have seen posts on this subject. I think Rex Grigg might have something for sale on his website..


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## magicmagni (Aug 19, 2004)

Well I was at aquaforest over the weekend and decided to bite the bullet on one the those nice ADA diffusers.

This is the one I got: Glass beetle 50









Having used a diffuser before (an off brand) and having sub- par results I was hesitant to try the ADA, but just in the last day I have been using it I can say that I am quite impressed.

For now I just disconnected the co2 from the reactor and have it going to the diffuser. I placed it near the bottom of the tank and the bubbles go right into the downward water flow of the spray bar, which blows the bubbles down into the substrate and across the tank. It is really quite amazing how all these little bubbles get blown all around the tank.

One thing I noted was that my PH is lower with the diffuser set up as I described. This is at the same bubble rate as before too so I was surprised thinking that reactors are generally more efficient? Ph went from a low of 6.5 with reactor to a low of 6.34 with the diffuser so it apparently quite effective. Not even sure at this point if I want to mess with a reactor anymore.


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