# Co2 Bubbles ruining the experience?



## PAYN3Y

Afternoon,

Recently I've been getting a bit disheartened with all the co2 bubbles in the tank. I originally started with an aquario in tank diffuser but have since swapped to a JBL in-line atomiser. I have done a PH profile previously and believe I have got the levels about right but the amount of nano-bubbles in the tank is really distracting. 

Once my co2 switches off my tank looks beautiful, the fish become instantly more active and the water looks none-existent. 

I've not really seen many other co2 injected aquascapes in real life so I'm not sure if this is just as prominent in every co2 tank. I think part of the issue is having the outflow, with the co2 bubbles, passing directly along the front glass of the tank. Perhaps it would be less distracting if the outflow could be positioned at the back of the tank?

Is a co2 reactor the only way around this? Do many people on here run them or do we all put up with the bubbles?


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## Ady34

I think if distribution in the tank is good it doesn’t matter where the co2 enters, the bubbles will still create the same issue. They also tend to be highlighted as they reflect the light. The mist is unfortunately a means to an end unless like you say you utilise other injection methods. They are very distracting, almost making the tank look milky at times and I agree once injection stops it’s a much nicer experience visually. Inline seem to be the worst culprits unfortunately, however that flaw is likely  the very thing that makes them a better option than an in tank diffuser as the micro bubbles are instantly chopped up further in the flow allowing them dissolve faster and more of them to reach the plants directly.
I tend to put up with them as without them the tank would look much worse all the time  I guess, I tried a reactor once but still found bypass. Again I think a lot depends upon how much co2 you have to inject to reach the desired levels. That obviously depends on many factors, lighting intensity, distribution, surface area, surface agitation, plant mass etc etc......
Some tanks will be less effected as they need to inject less, some look like a snowstorm 

Here is a video I took of a cherry shrimp feeding, you can see the micro bubbles for comparison....(best viewed in hd for detail)


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## PAYN3Y

Hi @Ady34 , thanks for the reply and completely I agree with everything you have said. My co2 looks pretty much the same as in your video. There are thousands of microbubbles all around the tank which is great for distribution but not nice for viewing. I only really enjoy the tank for the hour before lights out and it seems like the fish enjoy that hour much more too. I wish there was a better way.

I have my co2 come on 3.5 hours before the lights and my drop checker only get to bright green half way through the photoperiod.


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## Zeus.

I use twin JBL inline atomisers which then go though twin APS external filters set up as CO2 reactors. 
Tank bubble free except when the plants pearl or the Tiwnstar doctor is on


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## Ady34

Zeus. said:


> I use twin JBL inline atomisers which then go though twin APS external filters set up as CO2 reactors.
> Tank bubble free except when the plants pearl or the Tiwnstar doctor is on


I often thought about doing it this way round, do you ever get a filter ‘burp’ where excess co2 that builds up comes out in one go or do you get 100% dissolution? I think with the amount I inject I would get frequent ‘burping’ which would also be a waste. I guess as you run twin diffusers through twin filters then injection rate to each is low enough to allow the co2 to be fully dissolved?


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## PAYN3Y

Zeus. said:


> I use twin JBL inline atomisers which then go though twin APS external filters set up as CO2 reactors.
> Tank bubble free except when the plants pearl or the Tiwnstar doctor is on



That sounds interesting. I’ve been struggling to find much info on reactors. Most info I’ve read suggests they restrict flow too much and people end up going back to on take diffusers. Can you provide any more information? I’d be happy to pay a reasonable amount to have en effecient bubbleless co2 system.


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## Zeus.

Did a few tests









BPS rate



Plumbing to allow bypass so flow wasnt max thought the reactors keeping tank turnover as high as possible






Still work is in progress although it has stalled a little lately due to work. I dont think the JBL atomisers give me a fine mist at all as the operating pressure I use is too high, think its just a mass of big bubbles which get trapped in the APS EF2. I do get my pH drop in about 30mins ATM which is well over 1.5pH. One of the great benifits of using a PLC and a pH controler it it can/does give a much finer control of the CO2 injection rate as you can have lots of on/offs which change as the light intensity changes which enables the pH to hold to within 0.1pH from lights on till CO2 off.
I do use a lot of CO2 about 6KG a month but not as much as Clive did in the CO2 database.

My next plan is to modify the CO2 APS EF2 reactor with internal Venturi fitted so to remove the JBL atomisers and have a Venturri system similar to Evets one which will draw the CO2 in the reactors back to the ventri which will feed both reactors, CO2 inject large bubbles pre venturi, already got the pre designs in my head, the venturi will be on the diagram above just after the top 25mm Valve. Plus have fitted twin Maxspect Gyres the Filter output is irrelevent to the tank turnover as when the Gyres are off the tank turnover/flow is very low do to the output method.

It is surprising how low the flow can be though the CO2 reactors and still get a fast pH drop, plus need to read up on a few more ideas as well when I get the time 

Hope it helps


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## David Proctor

I'm having the same problem or maybe even worse judging from watching the video of the shrimp. I have been doing some research on this site and others and i'm thinking that moving my atomiser to the inlet of the filter maybe the way to go. I read a post here from George Farmer saying that he does this and it prevents any bubble reaching the tank. I see it mentioned that the filter media helps diffuse the co2 like you see in some reactors. Also my thought are in theory that when the flow enters the filter it's velocity will decrease due to increase in volume therefore pressure increase, co2 will dissolve faster at higher pressure. 

Some of the concerns raised with this are firstly the atomiser will clog quicker as dirty water pass through it; secondly co2 will degrade the seals in the filter; and lastly co2 will effect the beneficial bacteria. So my thoughts on the first point is to use a canister pre-filter before the atomiser purely for mechanical filtration to help prevent clogging. 
For the second point I have done some research and co2 is ok with nitrile seals (black o-rings) but will degrade silicone seals (orange o-rings) unfortunately my Eheim 2026 primer seal is silicone although the rest of the seals are nitrile. I managed to fine a website selling a nitrile seal for the primer all thought i'm interest to know why Eheim opted for a silicone seal there. And regards to the last points I recall George Farmer along with many others make the point that the plants themselves do the biological filtration and that the filter act to provide mechanical filtration as well as flow. I also cant find any evidence that adding co2 will reduce oxygen anyway.

Interested to hear people's thoughts.

On a side note my atomiser is a cheap Chinese one that doesn't seem to create a mist just lots of bubbles. I was considering buying a jbl atomiser, how have you got on with it? Do you keep a second ceramic ring to swap out for cleaning? Is it easy to clean?


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## Kezzab

I've done the co2/inlet thing and it works well. Depending on the filter you may find that it burps due to co2 collecting in the canister. Wasn't a big problem for me, but others on here have had it and it's been more annoying.


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## Tom Michael

I am currently having good success injecting though a canister filter - Ehiem 2217 in a 120 l. general conclusions are:


- I use an in tank diffuser directly into the intake, which in my mind maximizes contact time
-very occasional burping, for this tank it's also an indication I'm injecting too much
- much faster drop than in tank diffuser - half the time
- no current degradation to filter seals (4-5 months in)
- Ehiem handy as I can just about see what is happening through the green casing of the filter - towards the end of the injection period there is a small well of gas built up near the impeller 
- I use minimal filter media , 4 course foam pads
- some of the small bubbles make there way into the tank , this for me is a positive 

I'm about to set up an aquarium twice the size and I'm planning on experimenting with this injection method - and using 2 externals, one for filtration and the ehiem only for co2. I think it could be improved by adapting the impeller, removing the filter media, positioning the filter media so there are gaps inbetween each sponge, doubling the filter intake tubing to maximize contact time, allowing some of the co2 to also enter the water column (from experience there are benefits for direct contact)    

Thanks


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## Andrew Butler

Ady34 said:


> I often thought about doing it this way round, do you ever get a filter ‘burp’ where excess co2 that builds up comes out in one go or do you get 100% dissolution? I think with the amount I inject I would get frequent ‘burping’ which would also be a waste. I guess as you run twin diffusers through twin filters then injection rate to each is low enough to allow the co2 to be fully dissolved?


It will do your filter in Ady, tried it myself on G6 and then could never get back to 100% flow even without anything inline.
It must have the same effect on other filters, only we can see easily on the screen.


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## Zeus.

Had a little brain wave last night and moved the position of my chihiros doctor mesh to just below the filter intake, wasnt able to do it before but since fitting the maxspect gryes I have rise the filter intake position to near top of the tank as the gryes are handing the tank turnover easy. So a good 50% of the doctors output gets sucked into the filter, so I think the extra supply of O2 to the canister should help the aerobic bacteria filtration in the filter plus less fine bubbles in the tank too, so win/win IMO


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## PAYN3Y

Thanks for the replies everyone. It's certainly interesting to hear everyone's thoughts. I'm surprised there is a pre-manufactured device on the market aimed specifically at reducing or eliminating these pesky bubbles. At least one that doesn't restrict the flow too much.

This morning I have switched my JBL atomiser on to the inlet of my Biomaster 600. So far it seems to have eliminated most of the bubbles but I'll have a look again shortly when lights are on fully. I'll take note of the drop checker and PH readings to see if it makes much difference to co2 levels.



David Proctor said:


> On a side note my atomiser is a cheap Chinese one that doesn't seem to create a mist just lots of bubbles. I was considering buying a jbl atomiser, how have you got on with it? Do you keep a second ceramic ring to swap out for cleaning? Is it easy to clean?



JBL has been great for me. I have a second ceramic as I ordered the wrong size initially but I've never swapped them over. There was one occasion where the bubbles because a little larger but this was resolved immediately after I ran the pipe cleaner through to atomiser. The rest of the ceramic is spotless.



Zeus. said:


> Had a little brain wave last night and moved the position of my chihiros doctor mesh to just below the filter intake, wasnt able to do it before but since fitting the maxspect gryes I have rise the filter intake position to near top of the tank as the gryes are handing the tank turnover easy. So a good 50% of the doctors output gets sucked into the filter, so I think the extra supply of O2 to the canister should help the aerobic bacteria filtration in the filter plus less fine bubbles in the tank too, so win/win IMO



My newly acquired Twinstar Nano+ reactor is very near both my outlet and inlet. I may do as you say and move it closer to the inlet alone if you think that would be a good idea.


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## Daveslaney

My newly acquired Twinstar Nano+ reactor is very near both my outlet and inlet. I may do as you say and move it closer to the inlet alone if you think that would be a good idea.[/QUOTE]
I think I have read On the Twinstar website not to do this.


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## Daveslaney

Tom Michael said:


> I am currently having good success injecting though a canister filter - Ehiem 2217 in a 120 l. general conclusions are:
> 
> 
> - I use an in tank diffuser directly into the intake, which in my mind maximizes contact time
> -very occasional burping, for this tank it's also an indication I'm injecting too much
> - much faster drop than in tank diffuser - half the time
> - no current degradation to filter seals (4-5 months in)
> - Ehiem handy as I can just about see what is happening through the green casing of the filter - towards the end of the injection period there is a small well of gas built up near the impeller
> - I use minimal filter media , 4 course foam pads
> - some of the small bubbles make there way into the tank , this for me is a positive
> 
> I'm about to set up an aquarium twice the size and I'm planning on experimenting with this injection method - and using 2 externals, one for filtration and the ehiem only for co2. I think it could be improved by adapting the impeller, removing the filter media, positioning the filter media so there are gaps inbetween each sponge, doubling the filter intake tubing to maximize contact time, allowing some of the co2 to also enter the water column (from experience there are benefits for direct contact)
> 
> Thanks


I think if you fill the filter with plastic bac/ bio balls this would probably work best with this method.


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## Zeus.

Daveslaney said:


> I think I have read On the Twinstar website not to do this.



Cant think of a good reason for that advise !

So fitted my Chihiros Doctor reactor to the intake of my Fluval FX6



catches all the bubbles


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## PAYN3Y

So a full photoperiod just finished with the co2 directly into the inlet. No burping from the filter and no bubbles in the tank! Drop checker slightly more green/yellow than before. 

Need to keep an eye on it tomorrow as I may need to reduce the co2 timings before lights on. 

So far so good.


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## Daveslaney

No I can't either to be honest. But I'm sure I read it somewhere.


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## Zeus.

Daveslaney said:


> No I can't either to be honest.



Think I might have worked or of thought of a reason.

twinstars/Chihiros doctors are just basically 'Electrolysis of water'





So produce Oxygen gas, Hydrogen gas, H+ Ions and OH- ions

yes we wont the extra O2 gas to try and boost the [O2] but the H2 is potentially explosive if it collects in any volume the canister, so if they advised to have the gases go direct into the canister and 'IF' you canister 'exploded' it would be on their recommendation/advise, so it makes sense they advise you not to have it near the intake of the filter 'Just in case' so the H2 will just escape mainly from the surface of the water, so basically they are covering themselves IMO.

Been using the little mod for a day and the water in the tank is clearer tonight with that milky white appearance of the water you get when using the twinstars/Chihiros doctors has gone


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## PAYN3Y

Just thought I'd update this thread. 

After 3 days of firing the JBL inline directly into the inlet of my Biomaster there have been zero downsides. The co2 reaches higher levels quicker, there are almost no co2 bubbles in the tank and the filter doesn't 'burp' or hiss like I'd seen other mention.

Will it degrade my filter over time? Who knows! All I know is that my tank looks great throughout the whole photo-period, rather than just the final hour. Hopefully it doesn't negatively affect the plants.


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## Parablennius

I think I read somewhere that the carbon attacks O rings, gaskets etc?


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## PAYN3Y

Parablennius said:


> I think I read somewhere that the carbon attacks O rings, gaskets etc?



I've heard that too. But then read that it's usually the softer 'orange' O rings rather than black. To be honest I don't see that there is that much difference. My inlet is directly next to my outlet and my outlet was previously firing out thousands of co2 bubbles. There was that many bubbles in the tank that they're all going into the filter anyway so what is the difference? Granted there will now be more co2 in the filter but it's hard to say how much more. 

What's the worst that can happen? The filter loses power and/or starts to leak eventually? Time will tell. I'd happily replace the filter every 18 months if it kept the tank bubble free!


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## Kalum

interesting about the twinstar/doctor running directly into the inlet, i like it but...

are people doing this solely to benefit oxygenating the filter? would the oxygenated water that exits after passing through the filter return at the same levels but fully dissolved or would it potentially be higher/lower?

Reason i ask is the main purpose i use mine is to add additional oxygen for the fish/shrimp and don't want to do something that would be detrimental to that


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## ForestDave

PAYN3Y said:


> I've heard that too. But then read that it's usually the softer 'orange' O rings rather than black. To be honest I don't see that there is that much difference. My inlet is directly next to my outlet and my outlet was previously firing out thousands of co2 bubbles. There was that many bubbles in the tank that they're all going into the filter anyway so what is the difference? Granted there will now be more co2 in the filter but it's hard to say how much more.
> 
> What's the worst that can happen? The filter loses power and/or starts to leak eventually? Time will tell. I'd happily replace the filter every 18 months if it kept the tank bubble free!


Hi.
How's your filter doing? Have you noticed and downsides to running CO2 directly into it?
Thanks!


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## dw1305

Hi all,


Kalum said:


> are people doing this solely to benefit oxygenating the filter? would the oxygenated water that exits after passing through the filter return at the same levels but fully dissolved or would it potentially be higher/lower? Reason i ask is the main purpose i use mine is to add additional oxygen for the fish/shrimp and don't want to do something that would be detrimental to that


It doesn't make any difference to the aquarium / filter system, because you have the <"same bioload"> (and level of oxygenation) in either case.  

The advantage of the highly oxygenated water entering the filter is that it ensures that microbial nitrification (the conversion of NH3/NH4+ to NO3-) isn't <"limited by oxygen availability">. If the water becomes de-oxygenated in the filter you run the risk of ammonia levels building up in a positive feedback loop. When you have plants this is less of a worry, because you have "belt and braces" of the fixed nitrogen uptake by the plant / microbe "filter".

Purely in terms of the filter it would depend a little bit on the retention time of the bubbles within the filter and the Biochemical Oxygen Demand (BOD) of the filter media. If you had a short retention time, and a low BOD, then the water would have very similar oxygen levels when it left, to when it entered, the filter. As <"BOD and/or retention time increase"> the level of oxygenation will fall in the water that exits the filter. 

The ideal scenario is one where the water in the filter is 100% saturated with dissolved oxygen, but not supersaturated so that <"there are no bubbles of gas">. The only real issue with gas bubbles is that they can build up in the filter and cause <"burping", noisy running, impeller damage etc"> you can get with high levels of  CO2 injection. 

cheers Darrel


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## Zeus.

Kalum said:


> are people doing this solely to benefit oxygenating the filter?



No, gets rids tank of nano bubble mist as well. A Filter will low/no ceramic/fine media will also help increase flow in filter which will increase O2 levels in filter at the same time, which in turn help the microbial nitrification within the filter as Darrel points out.


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## Wookii

Zeus. said:


> No, gets rids tank of nano bubble mist as well. A Filter will low/no ceramic/fine media will also help increase flow in filter which will increase O2 levels in filter at the same time, which in turn help the microbial nitrification within the filter as Darrel points out.



Presumably it results in more DO in tank as well, as most of the bubbles from the Twinstar/Chihiros unit usually end up at the surface eventually rather than dissolving fully in the water column, so the extra contact time from them being trapped by the filter media presumably allows them to dissolve fully if you get no bubbles coming out of the filter outlet.


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## Zeus.

Wookii said:


> Presumably it results in more DO in tank as well,



Makes logical sense to me


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## dw1305

Hi all,


Wookii said:


> Presumably it results in more DO in tank as well, as most of the bubbles from the Twinstar/Chihiros unit usually end up at the surface eventually rather than dissolving fully in the water column, so the extra contact time from them being trapped by the filter media presumably allows them to dissolve fully if you get no bubbles coming out of the filter outlet.


Yes, that would be right, the only proviso is that we don't know what happens <"to the micro/nano bubbles">, they have the potential <"to damage the filter microbes">, but I assume this isn't a problem in practice. 

cheers Darrel


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## Zeus.

dw1305 said:


> Hi all,
> 
> Yes, that would be right, the only proviso is that we don't know what happens <"to the micro/nano bubbles">, they have the potential <"to damage the filter microbes">, but I assume this isn't a problem in practice.
> 
> cheers Darrel


Think there is the possibility of O3 (Ozone) production, which would kill all the bacteria in the filter/tank if the concentrations was high enough, but with the lack of positive/negative evidence either way I feel it is safe to presume all it does in rise the [O2].


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