# CO2 diffusion help needed...yes again...



## jojouk (14 Apr 2013)

Ok, so I have a large tank, 350l, 5ft long, and I need to increase my diffusion.

I currently have the co2 diffused by a ceramic diffuser in the middle of the tank on the rear, that feeds directly into an internal filter that in theory chops it up and blows it into the tank water. I have a Koralia nano above this to drive the bubbles down the front glass.

I also have 2 spray bars at the rear of the tank powered by 2 TT EX1200 to get that water flowing around the tank. I can post some pictures of the setup tomorrow if that helps.

Problem is, im not getting good enough diffusion of the co2. The bubbles are still quite large, and a lot of it still rises to the surface of the tank. I get my drop checker to lime green, but I need quite a high bubble rate to do this.

I am unsure what else to try. My regulator has a fixed pressure of about 1.75 ish, so I think its too low to get an UP Inline atomizer.

Any ideas?


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## GHNelson (14 Apr 2013)

Hi 
You can purchase a glass diffuser from ebay that fits onto the filter tubing.
 NAG-aqua music External Glass CO2 Diffuser(S)-Metal Clip is not include | eBay
hoggie


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## jojouk (14 Apr 2013)

That looks useful...but scary being glass!


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## tim (14 Apr 2013)

Hi jojo, with a tank your size I would look to use a reactor maybe with an external pump to push co2 all around your tank if you decide to use an inline co2 diffuser I think you'd need to have one on each filter and split your co2 for best distribution.


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## jojouk (14 Apr 2013)

tim said:


> Hi jojo, with a tank your size I would look to use a reactor maybe with an external pump to push co2 all around your tank if you decide to use an inline co2 diffuser I think you'd need to have one on each filter and split your co2 for best distribution.


 
I have been looking into making an external CO2 reactor, but I have very limited plumbing knowledge, so im struggling to find all the parts online


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## tim (14 Apr 2013)

Pm foxfish he may be able to point you to what you need check his signature for his DIY reactor very good build IMO if I ever get round to using a powerful enough  filter for my 90cm I would build one based on his design.


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## Tomfish (14 Apr 2013)

I agree, build a reator, i've built one for my 4ft and it made quite a difference. Little bubbles in big tanks don't seem to cut it. Good luck


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## jojouk (14 Apr 2013)

Dont know if this will work, but these videos show how the setup is at the moment. One is with a small spraybar attached to the internal filter, one is without


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## tim (14 Apr 2013)

Unfortunately those small bubbles will always want to escape. Have you considered buying a reactor, I know they aren't cheap but weighed up vs cost of wasted gas probably worthwhile in the long run.


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## Alastair (15 Apr 2013)

If you dont fancy going down the reactor route you could use a splitter on your co2 line and have two separate needle valves after this and run 2 glass diffusors under each filter inlet and have the filters themselves act as reactors


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## jojouk (16 Apr 2013)

Alastair said:


> If you dont fancy going down the reactor route you could use a splitter on your co2 line and have two separate needle valves after this and run 2 glass diffusors under each filter inlet and have the filters themselves act as reactors


 
I have been thinking of this also, but am worried about any negative effects on the filters themselves, the Tetratecs are a bit prome to getting air locks.


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## jojouk (16 Apr 2013)

I have been chatting to foxfish a bit about building a reactor, using a water filter housing? But would need a pretty large one for my tank size, so im thinking that I may build 2 smaller 10 inch ones for eaqch side. Would I need the 2 seperate needle valves for the co2 line?


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## foxfish (16 Apr 2013)

For a tank your size, useing my design you would need a 20" x 4.5" clear filter housing but they are not cheap unless you can find a second hand one.


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## jojouk (16 Apr 2013)

So you wouldnt advise using 2 seperate ones, one on each filter? I havent really got room to fit a 20" one anywhere


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## foxfish (17 Apr 2013)

You might find that a single vessel works ok but no doubt two would work better, possibly two in line with a single feed might do the trick?
The version in my vid is an unusual size being 12" x 5" but it handles quite a lot of gas before bubbles start escaping.
Every tank is different, I run a trickle filter & overflow on my 200l tank & use a lot of gas but my reactor have no problems at all keeping up!
However If you can arrange two separate reactors then that would be great.


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## jojouk (17 Apr 2013)

That's the plan then, two 10", one on each filter. 

Now to find all the stuff online....


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