# Difference between CO2 Reactor and diffuser?



## ddrfreak_tung (Sep 6, 2010)

IMO reactor, they can be external, max diffusion, and no soda can effect


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## Naekuh (Oct 19, 2011)

+1 to the op's question..

where is one needed more then the other...

or is the reactor just better overall?


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## Golightly (Jan 14, 2011)

ddrfreak_tung said:


> IMO reactor, they can be external, max diffusion, and no soda can effect


Oddly enough having a in-line diffuser seem to be more effective than a external reactor though. Now with the diffuser I inject less CO2 to accomplish the same PH level.

I'm interested in just finding out what's seen as more effective for plants.


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## kevmo911 (Sep 24, 2010)

If you see bubbles, you see non-diffused CO2. No bubbles, 100% diffusion.


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## Golightly (Jan 14, 2011)

kevmo911 said:


> If you see bubbles, you see non-diffused CO2. No bubbles, 100% diffusion.


I do understand that. But I can clearly see that the PH in the tank is lowered more efficiently when using a diffuser. I inject less CO2 to achieve PH 6.00. Yet the reactor dissolved all CO2, no bubbles seen.

Even so, what I'm interested in finding out is if the 100% dissolved CO2 is better or worse for plants than tiny micro bubbles that the inline diffuser creates. Those tiny bubbles lands and collects on the plants.


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## Jeff5614 (Dec 29, 2005)

Golightly said:


> I do understand that. But I can clearly see that the PH in the tank is lowered more efficiently when using a diffuser. I inject less CO2 to achieve PH 6.00. Yet the reactor dissolved all CO2, no bubbles seen.
> 
> Even so, what I'm interested in finding out is if the 100% dissolved CO2 is better or worse for plants than tiny micro bubbles that the inline diffuser creates. Those tiny bubbles lands and collects on the plants.


Current thinking, I think, is that mist might be a bit more effective due to the small CO2 bubbles on the leaves reducing the boundary layer and gaseous CO2 diffusing directly through the leaf. Of course I read a lot of stuff on here and other forums and sometimes it all runs together.


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## HD Blazingwolf (May 12, 2011)

no bubbles = 100% diffusion. correct. maybe there was a leak. all plants can take the dissolved form so either works butthe mist is good for some plants. rotala macranda, for example responds very well to it IMO


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## kevmo911 (Sep 24, 2010)

Golightly said:


> I do understand that. But I can clearly see that the PH in the tank is lowered more efficiently when using a diffuser. I inject less CO2 to achieve PH 6.00. Yet the reactor dissolved all CO2, no bubbles seen.
> 
> Even so, what I'm interested in finding out is if the 100% dissolved CO2 is better or worse for plants than tiny micro bubbles that the inline diffuser creates. Those tiny bubbles lands and collects on the plants.


That doesn't make sense to me. Bubbles mean that there is un-dissolved CO2 in the water, which means that less CO2 has been absorbed. Rational thought says that the pH should be lower with a 100% efficient external reactor at the same CO2 rate. If I had to guess, I'd say that somehow the bubbles are throwing the probe reading off, though I couldn't say how.

As for bubbles being more beneficial to some plants, that's possible. It seems odd, but I'm willing to go with it. I just haven't seen any evidence to back it up.


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## Golightly (Jan 14, 2011)

kevmo911 said:


> That doesn't make sense to me. Bubbles mean that there is un-dissolved CO2 in the water, which means that less CO2 has been absorbed. Rational thought says that the pH should be lower with a 100% efficient external reactor at the same CO2 rate. If I had to guess, I'd say that somehow the bubbles are throwing the probe reading off, though I couldn't say how.
> 
> As for bubbles being more beneficial to some plants, that's possible. It seems odd, but I'm willing to go with it. I just haven't seen any evidence to back it up.


I can't explain it either but the bubble rate I have now to achieve the same PH value as before is lower. I've recalibrated my PH controller and it's not that. The drop checker is also telling me the same. 

The UP Aqua inline Atomizer is very good actually, the bubbles are tiny and not like what you get with a standard diffuser.


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## inkslinger (Dec 28, 2003)

I'm thinking of going back to a reactor for my 110g tank and Eheim 2262 filter , I'm using a Atomic diffuser and my Bubble Count is very high IMO: the tiny bubbles go every where an also float up to the surface . where as a Aquariumplant.com has a house filter with a small power head inside to get 110% diffusion before it goes into the tank an others would comment that they don't see flow reduction .


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## willknowitall (Oct 3, 2010)

to state the obvious there are bubbles from using a reactor there just big and out of sight
with a inline atomic diffuser the whole tank is a big reactor
if the bubbles are very tiny they dissolve before making it to the surface

i have found 4 ways of decreasing the mist effect in the aquarium
1)faster flow
2) add length to output hose
3) up co2 pressure
4)add two diffusers (parallel)and lower bubble rate to each


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## kubalik (Jul 8, 2011)

maybe the little-bitty bubbles are fouling the ph controller/checker ....?


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## willknowitall (Oct 3, 2010)

kubalik said:


> maybe the little-bitty bubbles are fouling the ph controller/checker ....?


possible i could imagine tiny bubbles getting in to the drop checker
i have my ph probe inline before my diffuser , showing my diffuser is very efficient indeed


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## VeeSe (Apr 16, 2011)

Have you increased your working pressure on the regulator in order to accommodate the requirements for the in-line diffuser? If so, one "bubble" now contains more CO2 gas than before, so a lower bubble rate to attain the same pH drop may not mean a lower amount of CO2.


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## kubalik (Jul 8, 2011)

VeeSe said:


> Have you increased your working pressure on the regulator in order to accommodate the requirements for the in-line diffuser? If so, one "bubble" now contains more CO2 gas than before, so a lower bubble rate to attain the same pH drop may not mean a lower amount of CO2.


that makes sense to me too...


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## Golightly (Jan 14, 2011)

VeeSe said:


> Have you increased your working pressure on the regulator in order to accommodate the requirements for the in-line diffuser? If so, one "bubble" now contains more CO2 gas than before, so a lower bubble rate to attain the same pH drop may not mean a lower amount of CO2.


No, I've not increased the pressure. Same as before. But then co2 hose seems to be under more pressure if that makes sense. But why would the bubble which has the same size now and before, contain more gas? Never was very good at chemistry at school!

Anyway, it doesn't really matter. I'm more satisfied with the inline diffuser than the reactor. It means less equipment, higher output from the filter outflow and less noise. I was just wondering really if there was any difference for plants between the 2 delivery methods.


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## kevmo911 (Sep 24, 2010)

VeeSe said:


> Have you increased your working pressure on the regulator in order to accommodate the requirements for the in-line diffuser? If so, one "bubble" now contains more CO2 gas than before, so a lower bubble rate to attain the same pH drop may not mean a lower amount of CO2.


It doesn't work that way. Once the air gets past the needle valve, the pressure in the line will be the same as before you increased the working pressure (assuming there was air coming out at the end in the first place). So a bubble will contain the same amount of CO2 as it did before, because there won't have been any increase in back pressure from the end of the line. That's my understanding, anyway. But then again, I don't have any sort of hard science background.

I remember a very long, very physics-oriented argument about this some months back. A cookie goes to anybody who can find it


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