# CO2 inline diffusers



## parotet (18 Jan 2014)

Hi everyone, is anyone using this inline diffuser?
 Aquarium Glass Co2 Diffuser SK ATOMIZER SYSTEM II 12/16MM Live Plants Tank New | eBay

It is quite ugly compared to the CalAqua, but if it works it costs much less. I am considering to buy an inline diffuser like this because I have currently a standard ceramic diffuser under the inflow pipe. Any positive experience with this kind of inline diffusers? Will it improve my CO2 diffusion system? (Most of the bubbles go directly to the inflow pipe but a few ones escape... No problems with noises in the filter and I guess most of the CO2 is very well diffused thanks to the filter impeller. The above mentioned inline diffusers are fitted in the outflow pipe...). I'm quite happy with my pH drop and DC colour, but maybe There is still room for more improvement...
Have you tested other brands apart from CalAqua and the Hong Kong one?

Cheers,
Jordi


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## jose_j (18 Jan 2014)

Hi Jordi,

I haven't tried that system, but the main PRO I can see is that you will get your CO2 almost fully dissolved into your tank water compared with the standard ceramic diffuser. But I see also some CONS in that model. The main one is related with the direct injection of CO2 into the bacterial colony of the filter system, they are supposed to like O2, not CO2, so perhaps this can be problematic to some extent. I'm not an expert at all on this issue, but hopefully others members will have their say. Another CON could be the injury that the gas can cause to the filter pump itself. As you have already noted noise could also be another problem.

If you have a pressurized CO2 cylinder (instead of DIY yeast CO2) you could have a look to the inline CO2 atomizers that are installed in the inflow pipe, the one carrying clear water to the tank, so the gas is not forced to pass through the filter media.
I'm just trying to help you, but as I said I haven't tried it and I' not an expert at all ... I will follow this thread in order to learn from others members comments and suggestions.

Cheers,
Jose


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## parotet (18 Jan 2014)

Thank you for your reply Jose. What I have right now is a pressurized CO2 system with a ceramic diffuser under the inflow pipe. It has been discussed in other threads that if your canister burps, it depends mostly on the design of the canister and the injection rate. For the moment it works for me (Eheim 2215, 1.5 bps). Some members also explained that the bacteria colony won't be affected by CO2 levels... I cannot find the thread now but I think it was Clive who gave a long and detailed explanation, brilliant as usual. The problem I found is that I can see some bubbles reaching the surface, so it means that I'm losing part of the CO2. It is not really a problem but the system is not as efficient as it could be.

The inline injection system, such as the atomizers you mention, are said to produce a mist most people dislike. Honestly I have no experience with this but, as all of us, I would prefer to see the water in my tank as clear as possible. The inline diffusers I mentioned are connected to the outflow tubing, thus no potential burping, no glassware inside the tank and it is said that they do not produce mist. It looks like a perfect solution to me, especially if they are to be combined with spraybars, but of course if they really work.


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## Ben C (18 Jan 2014)

I've never used them Jordi, but the design make total sense to me. I think you'll be luck to get 100% diffusion with any system and would expect you to still get bubbles coming out of the outflow even with this one. I like the design and the further you can make the bubbles travel in the water column before entering the tank, the smaller they will be for you. I'd be tempted to go for it and see how you get on. Blaze the trail!


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## jose_j (19 Jan 2014)

Hi Jordi,

I'm sorry, I replied you without having done some research on that issue ..., thank you very much for all the information in post #3. Now I have seen a video of the glass diffuser you are talking about. I fully agree with Ben C, is not easy to get 100% diffusion with any system and making the bubbles trip longer in the water column will increase diffusion. In this video you can see that many bubbles reach the water surface, so I would not say that it is very effective anyway.

I'm using an inline atomizer and I have to say that the mist is not that dense, but of course it depends on the amount of CO2 you are injecting. I keep it working with at the minimum flow in a 300L densely planted tank and plants are doing well.

Thank you very much again for all the info and please keep us informed about how that device works if finally you decide to give it a try.

All the best,

Jose


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## parotet (19 Jan 2014)

jose_j said:


> In this video you can see that many bubbles reach the water surface, so I would not say that it is very effective anyway


Wow... haven't seen that. Thanks for the video. I though it was going to be much more effective. I think I have less bubbles reaching the surface with the ceramic diffuser under the inflow and the spraybar!
Is this mayve the secret of the CalAqua model (and the reason of that huge prize difference)?
Any CalAqua inline diffuser user to share with us its effectiveness?


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## ceg4048 (19 Jan 2014)

Yes, it is very effective as long as the inlet diameter of the spud is not smaller than the inside diameter of the connecting tubing. However, it is very expensive and is difficult to clean, not to mention it's fragility. I would continue to port gas into the filter inlet, which is a tried and has proven to be effective. Remove media from the filter to get better flow throughput.

Cheers,


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## Ben C (19 Jan 2014)

It would work better on the inlet tube, so the bubbles are rising into oncoming water and being forced down into the filter against the natural upward direction of travel. Just thinking
.. 

Sent from the comfort of my Samsung S III Mini. Wish it was an iPhone...


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