# Mist in tank when using co2.



## Richard Aldridge (20 Feb 2021)

Hi,
I've started using co2 in my tank and although there is a noticeable improvement in my plant growth I'm a bit disappointed that at 2 bps there is a large and noticeable amount of micro bubbles and it really spoils the appearance of the tank.

There's plenty of circulation in the tank and the bubbles are visible in all areas but I'm really considering going back to low tech rather than put up with the mist,also I seem to have a lot of surface scum now and I never had it before so is there something I can do or is this something you have to put up with?

By the way, I'm using a diffuser with the bubble counter and check valve built in.


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## DaveWatkin (20 Feb 2021)

If you have an external filter you can use and inline diffuser or reactor so the bubbles are absorbed before entering the tank. Or there are ladder types but they take up a little bit of room on the tank wall. 

Also it depends on the diffuser, I recently swapped to a twinstar and the bubbles are so much finer I don't mind them anymore.


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## Richard Aldridge (20 Feb 2021)

Thanks for your reply Dave, I did think about inline but it means cutting the return pipe and I've already had to cut mine to put double taps in,(Eheim 2215) so I don't fancy cutting the pipe again and having two joins in the same pipe.
I'll look at the twinstar diffuser as it can't hurt to have a spare diffuser can it,thanks for your advice👍


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## jaypeecee (20 Feb 2021)

Richard Aldridge said:


> I've started using co2 in my tank and although there is a noticeable improvement in my plant growth I'm a bit disappointed that at 2 bps there is a large and noticeable amount of micro bubbles and it really spoils the appearance of the tank.


Hi @Richard Aldridge 

What is the volume of your tank? And, are you losing much CO2 at the water surface because the water is turbulent/choppy? I ask because reducing the amount of CO2 being injected may be worth considering - less bubbles to create the mist. So, if you can minimize the CO2 loss, then you can reduce the amount of CO2 being injected without affecting the dissolved CO2 concentration. In one of my tanks, I use an horizontal ceramic rod diffuser (Bazooka). It is positioned below a streaming pump, which sucks the CO2 bubbles in and then blows them across the length of the tank. As a result, the CO2 dissolves in the water very quickly and the bubble size is very small - I would estimate much less than a millimetre in diameter. 

Hope this makes sense.

JPC


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## Richard Aldridge (20 Feb 2021)

Hi,
I have a Rio 125, about 100l I suppose, I'm using a Eheim external filter with a spraybar on the back wall pointing slightly down from the surface, slightly ruffling the surface but not enough to cause ripples,also I still have the internal filter which is 500l.

I have plenty of circulation as I can see the bubbles in plants so the circulations fine, I'm going to reduce the bubble count tomorrow to see if it does make a difference like you say and I'm looking to try a different diffuser.


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## jaypeecee (20 Feb 2021)

Hi @Richard Aldridge 

I assume that you use a drop checker to indicate dissolved CO2 concentration? What colour does it indicate at, say, around 10:00 AM? And, is your CO2 on a timer/solenoid valve setup?

JPC


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## Richard Aldridge (21 Feb 2021)

Hi,
I do have a drop checker in the tank but to be honest it's never shown any other colour than a dark blue colour,mainly because I never have more than 2 BPS owing to the amount of micro bubbles,but in actual fact despite the indication of the co2 being too low my plants have taken off,the leafs of my C.Balansae have grown so long they're laying on the surface and all my other Crypts are also doing well.

I'm going to turn the co2 down to 1bps today to see if the mist improves a bit and if it does I'll leave it at that,as George Farmer points out 'any co2 is better than no co2.


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## jaypeecee (21 Feb 2021)

Richard Aldridge said:


> I do have a drop checker in the tank but to be honest it's never shown any other colour than a dark blue colour,mainly because I never have more than 2 BPS...


Hi @Richard Aldridge

I have a 125 litre tank in which I normally run injected CO2 but the tank is awaiting a revamp so it's out of action right now. I used to run my CO2 at around 50 bpm and that would comfortably take the dissolved CO2 to around 25 ppm. Your tank is much the same size and you are running at 120 bpm. We need to bear in mind that not all bubbles are the same size. But, even then, I get the feeling that either:

1  Your injector is not doing a good job of getting CO2 into the water
2  Distribution of CO2 is perhaps not optimal
3  Excessive CO2 is being lost at the water surface

As for the drop checker, where is it located relative to the CO2 injector? Are you using 4dKH water in it with two or three drops of reagent? Using tank water in it is a no-no.

JPC


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## DaveWatkin (21 Feb 2021)

I run a 20L at 60bpm and get around 20-25ppm. 😳

Shallow tank though so loose a lot to the surface


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## Richard Aldridge (22 Feb 2021)

jaypeecee said:


> Hi @Richard Aldridge
> 
> I have a 125 litre tank in which I normally run injected CO2 but the tank is awaiting a revamp so it's out of action right now. I used to run my CO2 at around 50 bpm and that would comfortably take the dissolved CO2 to around 25 ppm. Your tank is much the same size and you are running at 120 bpm. We need to bear in mind that not all bubbles are the same size. But, even then, I get the feeling that either:
> 
> ...


It could actually be a distribution problem and I'm going to supplement it with a Tunze Turbellator which has a flow of something like 1000L p/h which will vastly improve the flow,at least it will blow the bubbles around more and I'm going to change the diffuser to a better one like a Twinstar.


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