Inline co2 diffusor question

[bojon]

Not sure if this should belongs here or the equipment group. anyhow 

I recently bought an inline C02 diffusor (still waiting for it), and I've been reading many forums about how to install this kind of diffusor. Almost all of them said they install it to the outflow of the hose line because they want to avoid the bubbles trap inside the filter and break it.

This is what I don't understand and confused me. First of all, if the diffusor is doing it's job properly, the bubble should be very fine. Secondly, the whole purpose of using it is to dissolve CO2 efficiently. If the bubbles are trapped inside the filter, is that even better? Because the flow of the current will help to dissolve them quicker.

Any input is appreciated 

[magnosis]

Providing the model / build of said reactor would help us to advise accordingly

Not that I'm an expert on the matter (far from it) but I'm on the same quest.  I've been reading quite a bit on CO₂ reactors lately and came upon this issue a few times.

Here are my two cents.

First advise would be to avoid relying on your reactor's efficiency, especially if there is a risk to damage your filter would the reactor start malfunctioning.

Secondly, the main problem I am working on right now with my reactor is the CO₂ overflow.  Generally speaking, any reactor can potentially buildup excess CO₂ bubble (for instance if the intake is not accurately tuned).  You should insure that your reactor has an overflow mechanism to expel any undissolved CO₂ (or other gas) buildup.

Not everyone agrees with this, but for the most part you should avoid excess CO₂ running inside the filter as it may interfere with the bio media and/or the proper functioning of the impeller.


That said, some people use their canister filter as a reactor in itself. I think this is largely dependent on which filter you are using and how the impeller is designed.  Do a quick google on "needle wheel diffuser", there are easy DIY mods that can be done on impeller blades to greatly improve CO₂ dissolution should you decide to go that way.

You can also take a peek at plantedtank.net, where I found more than enough information on the matter.  I hope it's not ill advised to refer other sites on this forum ... MODS: please remove this if I'm off-limits

[bojon]

Oh, the one I ordered is called Boyu, is a very cheap diffuser that I found many good comment from the same website you suggested 

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[charlie]

Oh, the one I ordered is called Boyu, is a very cheap diffuser that I found many good comment from the same website you suggested 

That specific diffuser is intended to be used either before or after the canister filter.
Some of the possible irritants of using it before the filter ( attached to the intake line) is the gurgling noise it can create in the cannister & also possible air lock depending on the qty of micro bubbles & filter design.

[Toss]

Yup, I had done it (intake) before with my DIY CO2. Charlie is right. It makes so much noise. I have Eheim classic series. It doesn't harm the filter, just noisy. When micro bubbles going through the media, it joins together to make a larger bubbles. Now I use pressurized and higher bubble count. I use the filter output as a reactor.

[bojon]

hi charlie,

so, in the ideal world (hehe i know there is not such place), it is better to set the diffuser to the intake?

thx,
jon

[bojon]

hi Toss,
U see, I think I just have to overcome the truth that the bubbles will never 100% dissolved. Currently I've my pressurized setup output to a ladder. I adjusted the ladder such that the bubbles coming out from it got suck into the filter's intake. I noticed that after the bubbles climbing up the ladder, their size almost reduced by 70%, even in such a short distance. So I thought if the bubbles have to travel through the whole filters and could blocked by all the media inside, they would be 99% dissolved inside the filter already...

jon

[charlie]

Jon , my understanding of these diffuser or better termed atomizers, is that they are meant to release the co2 via very tiny micro bubbles which Will float around the water column , in it`s travels around the tank 2 things are supposed to happen, they will continue to dissolve & some will lodge on the plant leaves, this will lead to direct absorption through the tissue.
I think you are applying the in line reactors method to these diffusers/atomizers, in line reactors are designed to completely  dissolve ( if that`s possible) the co2 into the water column.
Just my thoughts.

P.S.

some will lodge on the plant leaves, this will lead to direct absorption through the tissue.

Also known as "misting ", there is some arguments by the plantbrains out there, that is a better method of injecting CO2

[bojon]

Interesting charlie, I didn't know that misting is another good way..i guess time for me to read more.

[charlie]

Interesting charlie, I didn't know that misting is another good way..i guess time for me to read more.

Jon you can start here 
http://www.plantedtank.net/forums/general-planted-tank-discussion/35111-consensus-co2-mist-vs-inline-reactor.html

[bojon]

thanks charlie for the link. I did more reading this weekend about misting...i can't to give it a try..

[magnosis]

FYI, I just started on a new method this weekend and it's pretty good !

Just feeding the CO2 line in the venturi input of a Taam Rio RVT 800 pump (32$ from BigAlsOnline.ca). To the output of the pump, I attached a little piece of pipe hacked from an old HOB, terminated by a Fluval pre-filter sponge.

The mist that it creates is amazing for the simplicity of this setup. I get tons of tiny (0.1-0.5mm) bubbles just under the filter output, so they get pushed around by the current all across the tank.

[bojon]

Hey magnosis,

your DIY is a good way to diffuse co2 also. I've read about this setup on another forum and seems working pretty good. As long as u have a pump sitting around, this is an inexpensive way to do it.

From what i've read about misting this weekend, the output current is very important for a successful misting. Its seems to be better to let the micro bubble attached to the bottom of the leaves such that the plants can absorb the co2.

Because of that, I've moved my spar bar closer to the button of the tank such that when the bubbles come out, they get a higher chance to attach to the bottom of the leaves instead of reaching the water surface...well, i will see how this work out.

cheers,
jon

[magnosis]

the output current is very important for a successful misting. Its seems to be better to let the micro bubble attached to the bottom of the leaves such that the plants can absorb the co2.

Yes indeed. This is something I have to perfect. At the moment I only have 4 plants scattered at each end of my 55g tank, and the circulation is not quite enough to have the CO2 mist spread out evenly. So one plants gets 90% of the mist directly under it, and they other rely entirely on water circulation.  Maybe instead of one mist output, I should use line splitters and have the mist output divided between 2 or 3 outputs.

To be continued