Bubbler while injecting co2 - hear me out.

JoshP12

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Hello fellow friends of UKAPS,

I am having an internal dilemma regarding this issue.

In my journal, I mentioned some observations that I have made with dissolved oxygen (using a probe, I was amazed at the impact that my bubbler had on levels, albeit this was done in a tank free of plants and fish).

I can provide several links, but I am going to make some statements based on some things I have read:

1) Tom Barr prefers the use of “sealed-Ish” wet-dry filters in his sump for gaseous exchange - many people fear for driving off co2. He further claims that his high levels of co2 are possible because of his DO levels which are around 7-8 ppm (nearly maxed).

2) Ceg (who I have not met but love reading his posts) uses a spray bar and time and time again suggests flow distribution and surface agitation increase overall health of aquarium. His spray bar waterfalls onto the surface of the water column. I’ll be honest, I am considering a spray bar and if I had one I would consider removing the bubbler. These same ideas are echoed by several well-respected members on UKAPS.

3) Dennis Wong extensively talks about the necessity for gaseous exchange for stable aquarium.

4) ADA Lilly bar positioning making a little vortex to make gaseous exchange more possible.

5) Henry’s law to discuss equilibria.


Now, a bubbler (the one I have is embedded into my power head) will increase gaseous exchange at the surface and as a result ensure high DO levels but also force my dissolved co2 to get to equilibrium of 3ppm—unless I pump it in faster.

I have 2 options:
1) run it during photoperiod + at night (all day)
2) run it only during night (not during photoperiod)

The only benefit to 2 is that I will not off gas co2 and my co2 tank will last longer — what this also means is my DO levels may decrease during this time (except the oxygen released by plants will probably keep my levels high enough, if I pick option 1).


What I am interested in is having a healthy system.

If I do not have sumps/spray bars/have a fast-flowing shallow tank (like a river or stream), is using the bubbler a “nice” equivalent alternative.

I attached a picture of the bubbler in the tank for a visual.

So, I think the answer is that both strategies will work - but which one will be better?

I am posting because I have not yet read a thread where some one is advocating for option 1, and I don’t think it’s that outlandish (but if it is, please let me know, ha).

Cheers,
Josh
 

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JoshP12

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Since I am amidst the starting stages of my tank (crucial to establish the system for what I want), I am going to throw the bubbler on a timer and pursue option 2; it will be much easier to increase surface agitation and match it with co2 later (after I have some input) rather than remove surface agitation and guess for co2 decrease.

I raised from 2-3 bps by the end of the day yesterday in search of dialing in that co2 — in the 65 gallon, this should be totally fine for my current livestock. I will watch the first bit of the photoperiod and the drop checker for any adverse effects.

If I see anything, I can just flick on the bubbler to save me some troubleshooting time.

Josh
 

jaypeecee

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Now, a bubbler (the one I have is embedded into my power head) will increase gaseous exchange at the surface and as a result ensure high DO levels but also force my dissolved co2 to get to equilibrium of 3ppm—unless I pump it in faster.

Hi @Plants234

For my benefit, please tell me more about the 'bubbler'. What does it do? Is it a CO2 diffuser? And did you really mean 3ppm or should that be 30ppm? What is your overall objective? I know you say that you want 'a healthy system' - healthy in what respect? Sorry for what may seem as silly questions.

JPC
 

jaypeecee

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Hi @Plants234

Just realized that the bubbler is an air stone! Yes, it produces air bubbles but just never heard it referred to as a bubbler.

My only remaining question is about the 3ppm figure.

JPC
 
Last edited:

JoshP12

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Canada
Hi JPC!

Hi @Plants234

Just realized that the bubbler is an air stone! Yes, it produces air bubbles but just never heard it referred to as a bubbler.

My only remaining question is about the 3ppm figure.

JPC

My reference to the 3ppm is for co2 if there was injection - I.e. equilibrium with atmosphere.

Each surface break from the bubbler causes me to off gas my higher concentration co2 in the tank to the lower concentration with the atmosphere - so my injection rate will need to be so high that I can overcome this during my photoperiod and keep my ppm of co2 “nice” - whether that is 30 or higher, I am not worried.

The ultimate question is: is the higher injection rate of co2 WORTH the benefit of increased surface agitation during the photoperiod (for all of my aforementioned arguments) - every post I read - not on UKAPS, (and it is likely I am not reading the “right” ones) suggests blindly, and I say that not as an aggressive comment but as an observation almost like my un-cited statements that I provided, to NOT run the bubbler to not off-gas co2 ... but who care about off gassing co2, if the overall health increases?

Aside from filling the co2 tank more often.

cheers,
Josh
 

dw1305

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Hi all,
what this also means is my DO levels may decrease during this time (except the oxygen released by plants will probably keep my levels high enough, if I pick option 1).
You don't need to worry as much about oxygen levels during the photoperiod, unless you have a very small plant mass.

Plants are very effective at oxygenation, you can even get <"cyanobacteria pearling in sewage treatment"> when the sun is out. <"A question......"> might also be of interest.
I have made with dissolved oxygen (using a probe, I was amazed at the impact that my bubbler had on levels, albeit this was done in a tank free of plants and fish).
That's is a real dramatic example of the effect of increasing the gas exchange surface area.

a05273f0-8bdd-49c6-a806-395183e9ce56-jpeg.jpg


cheers Darrel
 

JoshP12

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Canada
Hi @Plants234

No, it's not an air stone! You clearly said that "the one I have is embedded into my power head". Put all my ramblings down to what might be called a 'senior moment'!

JPC
Haha! No problem.

I suppose when I say healthy, I mean balanced.

With higher gaseous exchange, my gas levels (oxygen is what I am most concerned with) are constantly being put “back in check” — So I never deplete those oxygen stores and my likelihood of gassing fish decreases (since O2 levels are dictating how much co2 I can inject) - or I can add “more” co2, which I am not worried about doing unless I have more demanding plants.

A note here: If my bubbler malfunctions, then the levels of co2 that I am used to injecting will certainly kill everything —- so it may be safer to NOT run the bubbler during the photoperiod - they are in the same power bar so the malfunction of timer/bubbler are the only issues.


Now, I make note that the plants will restore the O2, so do I even need to worry about that?

More and more, I am leaning towards, “I will try it with option 1 and if I can test this theory later.”

In my test earlier, it took about 6 hours to drop my DO levels down about a point —> sooo... from 8.2 ppm oxygen down to 7.2 ppm oxygen by the end of the photoperiod should be sufficient.

Josh
 

JoshP12

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Hi all, You don't need to worry as much about oxygen levels during the photoperiod, unless you have a very small plant mass.

Plants are very effective at oxygenation, you can even get <"cyanobacteria pearling in sewage treatment"> when the sun is out. <"A question......"> might also be of interest. That's is a real dramatic example of the effect of increasing the gas exchange surface area.

a05273f0-8bdd-49c6-a806-395183e9ce56-jpeg.jpg


cheers Darrel

Thank you Darrel!

Timer it is then?
 

dw1305

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Hi all,
Timer it is then?
I'm not a CO2 user, but that would be the route I went down if I was. You would get a rapid pH rise as the O2:CO2 ratio swung in favour of oxygen, some-one else will have to tell you if that is a problem in practice.

cheers Darrel
 
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