DIY CO2 HOB Filter Diffusion

[Cerianthus]

CO2 and O2 do not compete. Plenty of people diffuse CO2 through a filter. I have done it through a canister myself.

What do you mean by they do not compete? Of course it will affect one another. Its not a competition but rather volume of stable dissolved gas that water can sustain in given environment (simple analogy, warmer water has less dissolved O2 than cooler water).
Try testing for [O2] in the tank after CO2 are diffused into water with no other factors changed and compare to tank with no CO2 injection.
[CO2] and [O2] are affected by each others and other dissolved gases and other factors etc, etc..
I was more concerned with availability of O2 for aerobic BB in an environment with higher saturation of dissolved CO2. Why take a chance by injecting CO2 into such when it can be avoided.
There are instances where this way of injection may cause enough disturbanceswhere other factors can contribute to disaters over night or when you are not home, especially with DIY system where injection is not properly controlled/monitored....

Lot less or no implications/complication yielded when CO2 are injected on return tubing right above the filter..

 

[jpappy789]

At the levels we are talking about here there is certainly no issue.

 

[Cerianthus]

At the levels we are talking about here there is certainly no issue.

thats what you think but untrue. Principles are the same wherever it may be applied to.

Like I said, other factors are very critical in outcome and from time to time, it is beyond our control, especially with DIY and one filter tank.

No argument with your system on its ability but why risk it when safer condition can bre achieved with simple modification.

 

[247Plants]

co2 and o2 are not dependent on each other in the water column. Low o2 does not mean that high levels of co2 are present and vice versa.

What you are getting at is total volume of gasses that can be dissolved in the water.

Each can reach saturation without pushing the other out though. The bubbles in carbonated soda are an excess of co2 saturation. What we call pearling in planted tanks is an excess of o2 saturation in the water column. Yet we can still inject co2 and keep a steady 30 ppm or so....I imagine even higher if you wanted.

At consistent co2 levels, it doesnt matter where you inject really since the water being pulled in by the filter and passed over the filter media is saturated with co2 already.

 

[jpappy789]

I read that O2 can reach 120% saturation while keeping a steady 30 ppm of CO2. Whether that is true or not, I don't know, but Kurtis hit it right on the nose.

 

[Cerianthus]

Constant 120% O2 in open fish tank with water movement, lmk if possible. If possible =, fish would be dying from O2 poisoning!!!

Just search effect of CO2 on aerobic nitrifying bacteria. Yes, [CO2] will be even eventually once injection stop but until then, injection area itself will be in higher [conc] than rest of water.


As far as how [CO2] and [O2] and other gases affect each other, search ReDox.

No open carbonated bottles will stay bubbly. Why?

 

[247Plants]

Constant 120% O2 in open fish tank with water movement, lmk if possible. If possible =, fish would be dying from O2 poisoning!!!

Just search effect of CO2 on aerobic nitrifying bacteria. Yes, [CO2] will be even eventually once injection stop but until then, injection area itself will be in higher [conc] than rest of water.


As far as how [CO2] and [O2] and other gases affect each other, search ReDox.

No open carbonated bottles will stay bubbly. Why?

As far as the higher concentration areas, the bubbles of co2 usually pass through the filter unchanged, its when it hits the impeller pushing the water back out into the tank where the bubbles get chopped up into mist where the concentration is highest and seeing how this point is past the media I dont see an issue. It still takes some time for the co2 to get fully dissolved even beyond this point anyways.

Redox isnt really an issue when we are talking about the co2 and o2 levels in an aquarium. We arent oxidizing anything either per say so redox doesnt really apply in any of this talk about the capacity of water to hold different gasses. Maybe Im wrong and you can help me out.

The reason open carbonated bottles will not stay bubbly is that the co2 present in the bottle is trying to reach equilibrium with the atmosphere. No big secret there. Same reason o2 and co2 are outgassed in our aquariums.

 

[jpappy789]

Constant 120% O2 in open fish tank with water movement, lmk if possible. If possible =, fish would be dying from O2 poisoning!!!

Just search effect of CO2 on aerobic nitrifying bacteria. Yes, [CO2] will be even eventually once injection stop but until then, injection area itself will be in higher [conc] than rest of water.


As far as how [CO2] and [O2] and other gases affect each other, search ReDox.

No open carbonated bottles will stay bubbly. Why?

I'm not saying that it would happen in a tank. Just that adding the normally recommended concentration of CO2 is not going to dramatically limit the amount of O2 in the water column.

 

[Slappy*McFish]

I agree. Adding CO2 (within reason) does not reduce/replace/displace O2 in the water column. It can, however, reduce the O2 available to the fish's blood even in an O2 saturated tank.

 

[park83]

Back to my original question

What i really wanted to know is will the CO2 be dissolved and carried into the tank through my power filter (Emperor 280), or does this type of filter allow for it to gas off too much before it even hits the tank, and am I better with the airstone or a powerhead doing the diffusion?

My bubble counter is showing slightly less than 1 bubble/second, so I do not believe I am in the realm of overdosing - even with a very efficient transfer.

Thanks,
Brian