Using CO2 Efficiently

jaypeecee

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Hi Folks,

I would like to improve the efficiency of my CO2 usage. I have two related areas of concern:

1 Solubility of CO2 into the tank water

I use an internal ceramic atomizer (Bazooka) that produces a very fine mist of CO2 but, despite this, the microbubbles don't completely dissolve. I use a circulation pump which does an excellent job of moving water around the tank.

2 Loss of CO2 at the water surface

As a consequence of item 1 above, a good many CO2 microbubbles find their way to the water surface at which point they burst. The circulation pump and external filter flow outlet cause only gentle surface agitation - just enough to allow some CO2/O2 exchange.

I have avoided inline CO2 diffusers as I have read of too many horror stories of these malfunctioning thus causing major leaks and flooding. I am also unsure if they do a better job of diffusing CO2 into the water as dwell time is very brief unless the reactor type is used.

Any suggestions?

JPC
 

tiger15

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CO2 mist is not all that bad as Barr has demonstrated that plants can uptake mist falling on the leaves more efficiently than dissolved carbonic acid. All Amano set ups use CO2 misting.

As for CO2 gas bubbles bursting on the surface, it's a loss of no return in open top set up. But in covered top set ups, I am in the opinion that some lost CO2 is recovered, but I have no data to prove it.

https://www.ukaps.org/forum/threads/tank-cover-good-or-bad-for-co2.56065/

I agree with you that any in line reactor is vulnerable to leak and for that concern, I don't use it. If a leak is developed in the plumbing and you don't catch it early, even a slow leak can drain the tank. I use Tunze reactor, which employs an in-tank power head to drive the reaction, and without external plumbing, there is no opportunity to leak.
 
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As @tiger15 said, there is some benefit to having CO2 mist coming into contact with leaves. This video might be helpful:

You could also look into building your own Cerges or Griggs reactor. The qanvee inline diffusers also look pretty sturdy.
 

Edvet

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A reactor will be very efficient in dissolving CO2, the more CO2 you use the larger reactor will make it easier. You can DIY a reactor to suit your demands. When i was using CO2 in my 400m gallon I made one about 125 cm long. Member Zeus here made a double setup.
 

TBRO

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+1 on the reactor. Seems to be the only way to get a decent pH drop in my tank without literally pouring in CO2 with the valve open!

I think a few of Amano’s big tanks must use some kind of in line solution, maybe between the sump and tank?


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I combine using a bazooka which is the finest mist I've experienced using all the various atomisers on offer and keeping all the equipment in one corner in so far as the intake, lily pipe outlet and bazooka. I have them set up with the bazooka under the intake so it can grab some of this mist and pull it down into the canister to dissolve further and any that manages to get past the intake hits the flow of the out flow and gets pushed round the tank. I guess it's a little bit more effective than say having the bazooka on the opposite side of the tank to the outlet like you see in most setups.

Dissolving co2 is a very wasteful process at the best of times. The vast majority of it just leaves the tank without doing much. Co2 gas just doesn't like living in warm water. It doesn't even want to live in a freezing cold drink for very long. Just wants to enter the atmosphere and play with all the other gases.
 

Oldguy

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inline CO2 diffusers
I have two inline diffusers, but both are in the tank, with power heads pushing tank water through them. One exhausts through a spray bar, the other through a fish tailed pipe. I too have read about leaking external diffusers hence some rearranged plumbing to get to present set up. I use cover glasses to reduce condensation. Don't know if they enhance CO2 retention. Fish stock appear healthy & active.
 

tiger15

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I use Tunze reactor, very well made German product. It runs on internal power head and generates about 80/20 dissolved and misty CO2. I guess you can increase dissolved by extending the pipe, but I rather have 80/20 split, and have a glass top to recover some escaped CO2. My planted tank is in my living room, and I have zero tolerance of leak. My filters are multiple HOBs, and I don’t even trust running external canister filters, which IMO is a dangerous equipment that can drain a tank overnight. Even my CO2 hose check valve is placed inside the tank. By eliminating external plumbing, I eliminate all opportunities to leak.

upload_2018-12-26_10-14-28.jpeg
 

jaypeecee

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As @tiger15 said, there is some benefit to having CO2 mist coming into contact with leaves. This video might be helpful:

You could also look into building your own Cerges or Griggs reactor. The qanvee inline diffusers also look pretty sturdy.
Hi Oscar,

Thanks for your reply.

The video is very good indeed. I'll check out the Cerges and Griggs reactors.

JPC

Hi
You could add floating plants for more Co2 retention!
hoggie
Hi hoggie,

Thanks for your reply.

Your suggestion of adding floating plants is a good one. Never thought of that!

JPC

A reactor will be very efficient in dissolving CO2, the more CO2 you use the larger reactor will make it easier. You can DIY a reactor to suit your demands. When i was using CO2 in my 400m gallon I made one about 125 cm long. Member Zeus here made a double setup.
Hi Edvet,

Thanks for your reply.

Using a reactor presents a problem for my setup. The cupboard in my aquarium cabinet is already stuffed with gear so I could only accommodate the smallest of reactors.

JPC

+1 on the reactor. Seems to be the only way to get a decent pH drop in my tank without literally pouring in CO2 with the valve open!

I think a few of Amano’s big tanks must use some kind of in line solution, maybe between the sump and tank?


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Hi TBRO,

Thanks for your reply.

Out of interest, what pH drop do you aim for? I've read elsewhere on UKAPS that people aim for a drop of 1pH but, at some KH values, that would result in a CO2 concentration well in excess of 30ppm.

JPC

I combine using a bazooka which is the finest mist I've experienced using all the various atomisers on offer and keeping all the equipment in one corner in so far as the intake, lily pipe outlet and bazooka. I have them set up with the bazooka under the intake so it can grab some of this mist and pull it down into the canister to dissolve further and any that manages to get past the intake hits the flow of the out flow and gets pushed round the tank. I guess it's a little bit more effective than say having the bazooka on the opposite side of the tank to the outlet like you see in most setups.

Dissolving co2 is a very wasteful process at the best of times. The vast majority of it just leaves the tank without doing much. Co2 gas just doesn't like living in warm water. It doesn't even want to live in a freezing cold drink for very long. Just wants to enter the atmosphere and play with all the other gases.
Hi AWB,

Thanks for your reply.

Glad to meet another Bazooka user! I have been a bit hesitant about locating the Bazooka near the filter intake. I thought the CO2 could get partially trapped in the external canister causing it to 'cough and splutter'. Love your analogy about CO2 entering the atmosphere and playing with all the other gases!

JPC

I have two inline diffusers, but both are in the tank, with power heads pushing tank water through them. One exhausts through a spray bar, the other through a fish tailed pipe. I too have read about leaking external diffusers hence some rearranged plumbing to get to present set up. I use cover glasses to reduce condensation. Don't know if they enhance CO2 retention. Fish stock appear healthy & active.
Hi Oldguy,

Thanks for your reply.

I also have cover glasses but they have cutouts at the two rear corners. I think it's unlikely that any CO2 is retained.

JPC

I use Tunze reactor, very well made German product. It runs on internal power head and generates about 80/20 dissolved and misty CO2. I guess you can increase dissolved by extending the pipe, but I rather have 80/20 split, and have a glass top to recover some escaped CO2. My planted tank is in my living room, and I have zero tolerance of leak. My filters are multiple HOBs, and I don’t even trust running external canister filters, which IMO is a dangerous equipment that can drain a tank overnight. Even my CO2 hose check valve is placed inside the tank. By eliminating external plumbing, I eliminate all opportunities to leak.

View attachment 120244
Hi tiger15,

Thanks for your reply.

The Tunze reactor does look interesting. I will check it out. Although I use an external canister filter, I have set up a low voltage water level sensor that switches off the filter if a leak occurs in the filter pipework or the tank itself. I also have a water leak alarm in close proximity to the filter itself. So, keeping my fingers crossed.

JPC

To make the most of CO2 injection, the best thing I read is 'you need to use it as CO2 is free' only then will you use it to its full potential ;)
Hi Zeus,

Thanks for your reply.

Where can I find your reference to 'you need to use it as CO2 is free'?

JPC
 
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Zeus.

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Out of interest, what pH drop do you aim for? I've read elsewhere on UKAPS that people aim for a drop of 1pH but, at some KH values, that would result in a CO2 concentration well in excess of 30ppm.
a drop of 1.0pH is what is generally advised. My pH drop is well over 1.0pH and my DC is light yellow which can be risky with some livestock. Good surface agitation does seem to help with the higher pH drops for the livestock, but the plants do benefit from higher [CO2]'s . its down to the user plus you do need to try and get the correct pH when the tank has fully degased to know you have acutally got a one unit drop as some tanks take longer than overnight to degas, plus not all pH testing methods are accurate, DC is the best method to see what the approximate pH/[CO2] is IMO/IME

Where can I find your reference to 'you need to use it as CO2 is free'?
pH is IMO/IME

No idea m8 where it was :oops: it was one of the many many posts I read when I started.
 

jaypeecee

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Thanks, Zeus. I'll find the post. Perhaps the livestock can tolerate the higher CO2 levels provided that the O2 level is also high (around 8ppm)?
 

tiger15

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Hi tiger15,

Thanks for your reply.

The Tunze reactor does look interesting. I will check it out. Although I use an external canister filter, I have set up a low voltage water level sensor that switches off the filter if a leak occurs in the filter pipework or the tank itself. I also have a water leak alarm in close proximity to the filter itself. So, keeping my fingers crossed.

JPC
Interesting, you’re the only one I know of that install leak protector for your canister set up. Avoiding in line reactor is a smart move, specially unproven DIY design. It reduces risk but not a full proof though. What if water siphons back from the tank to the leak point after the shut down. Also, alarm works only if you’re home and can hear it. I don’t want to scare you but the only leak proof is to avoid any external plumbing in the first place.
 

Zeus.

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some of my fish are gasping at the surface at the end of the pH drop but they soon settle down after 15mins and they have been in the tank over a year
 
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Glad to meet another Bazooka user! I have been a bit hesitant about locating the Bazooka near the filter intake. I thought the CO2 could get partially trapped in the external canister causing it to 'cough and splutter'.
I find with the Bazooka the mist is that fine by the time it gets down into the canister travelling through the pipe work its nigh on non existent. Not all of the bubbles get in there either. I don't have issues with it collecting or the filter burping although I have heard some people have, not sure which atomiser they were using and the bubble could have been bigger.

It depends on how you feel about equipment in the tank. A lot of the reactor type devices like the Sera and similar can be placed inside of the tank on the glass negating the risk of flooding. Some of the newer inline ones seem to be built with metal hose connections so should be safer although I have no experience with these...yet.
 

jaypeecee

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Interesting, you’re the only one I know of that install leak protector for your canister set up. Avoiding in line reactor is a smart move, specially unproven DIY design. It reduces risk but not a full proof though. What if water siphons back from the tank to the leak point after the shut down. Also, alarm works only if you’re home and can hear it. I don’t want to scare you but the only leak proof is to avoid any external plumbing in the first place.
Hi tiger15,

Your point about back-siphoning is one that I need a bit longer to think about. Perhaps a non-return valve would be the answer but that would need to be in the tank just in case it leaked! You're partly right about the alarm but some can be WiFi connected, which should enable alerts to be sent to a mobile phone, for example. At the end of the day, nothing is 100% safe. After all, a leak can develop in the tank itself. As with all things in life, it's a question of striking a balance.

JPC
 

tiger15

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There is an anti siphon hole you can drill into the intake pipe, so if there is a leak, the canister can only lower the water level to certain limit before pumping dry.

Yes, even with all precautions, the tank seam can leak, and it does happen. So don’t keep any tanks or place them in the garage or basement where flooding doesn’t matter. This is equivalent to saying don’t drive because there is no accident proof driving. But a show tank is a living art, a piece of furniture to show off, so why hide it in the basement no one can appreciate. So it’s my calculated risk to place my show tanks in the living room but I take maximum precautions to minmize flooding accident.
 

Hades

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My planted tank is in my living room, and I have zero tolerance of leak. My filters are multiple HOBs, and I don’t even trust running external canister filters, which IMO is a dangerous equipment that can drain a tank overnight. Even my CO2 hose check valve is placed inside the tank. By eliminating external plumbing, I eliminate all opportunities to leak.
It's a bit strange to me to stress that much about a possible leak to that extent that you avoid any inline equipment..?
Especially because you say it yourself:

But a show tank is a living art, a piece of furniture to show off, so why hide it in the basement no one can appreciate.
If you want to show off the tank you don't put it in the basement, i agree, but for me the same logic applies for all in tank equipment.
After all the equipment is not what you want to show off, is it? :rolleyes:
It doesn't do the "living art"-part any justice if you have internal filters or HOB (which can also leak by the way... :crazy: ), internal reactors or any internal plumbing imo.
Clearly visible equipment doesn't really enhance the look of any tank for me.
I can't really enjoy a tank riddled with in tank equipment so it's not even an option for me, ever...
I have canister filters (5 atm) with inline equipment in my living room for years and never had any leaks. :bored:
For me canister filters and such hold the same risk as a possible leak in the tank itself. (Or a HOB cracking and leaking...) It's part of the game...
And let's be serious: it happens rather rarely provided the proper material, good care and caution so why compromise?
;)
If you don't want anything leaking and you stress about it that hard that you desperately want to eliminate all the opputunities to leak... then you are not there yet i guess, the possibility is still there.
So, it might be better (or even needed) to put some flowers or some plants in your living room instead of a tank filled with water (wanting to get out)... :lol:
But beware: don't over-water those plants though cause the pots might leak a bit... ;)
 
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