Do you add 02 to your planted tanK?

[mphunk]

I am just curious in anyone adds oxygen to their planted tank. Specifically through a pump/airstone. If so why? If not why?

I add CO2 and ferts...but test really low on dissolved oxygen levels. Which, in nature, is a guage in stream health and monitored in many preservation efforts. Just wanted to hear any theories before I start my own controlled experiment in my idol (my wife's nickname for my tank:headshake2:).

Thanks for your replies!:headbang2:-Matt

[Mgamer20o0]

nope. the plants should be making plenty of o2.

[mphunk]

I knew you would be first to post....that was my thoughts. I wonder if my overstocking is lowering my oxygen levels? (answering my own question)

[Mgamer20o0]

shouldnt be. are you seeing your fish gasping for air? never tested for o2 levels.

[Orlando]

Negative

[mphunk]

shouldnt be. are you seeing your fish gasping for air? never tested for o2 levels.

Yes I have a dissloved oxygen test kit, HACH sent it to me as a thank you (my company orders alot of testing chemicals)
My fish (only cories) occasionally surface, then quickly bolt back down. I wonder if testing at night would change the 02 score. (thinking along lines of respiration):idea:

[Mgamer20o0]

cories do that. if the fish look fine i wouldnt worry too much about it.

and co2 and o2 are independent of one another.

[Beasts]

But if the oxygen level tests low wouldn't it be best to correct the problem? The fish may not be gasping but the entire system - fish, aerobic bacteria, plants (when dark) - would function better given a healthier oxygen concentration. Something as simple as redirecting the outflow from your filter to move more water to the surface might solve the "problem."
Plants, in the dark, are net oxygen users and, therefore, will tend to drive oxygen levels lower when the lights are off. They produce oxygen as a byproduct of photosynthesis. I have never heard of anyone adding oxygen from a tank (cylinder) to an aquarium but we all do it whenever we move the water around with filters or airstones. Changing the water at the surface is of primary importance as that is where most gas exchange occurs. The drawback is that this will also result in some additional CO2 loss.
Beasts

[Squawkbert]

co2 and o2 are independent of one another.

Eh - not quite. When the lights are on, plants consume CO2 and give off O2 in the process. When the plants are in the dark, they respire, consuming a bit of O2 as catabolic processes continue in the absence of photosynthesis. They give off a tiny bit of CO2 in the dark as well.

[GirlieGirl8521]

MG probably means that CO2 doesn't displace O2.


I am just curious in anyone adds oxygen to their planted tank. Specifically through a pump/airstone. If so why? If not why?

Nope. There is not a need to IMO. And having alot of surface agitation from an airstone can outgas any CO2 that you are injecting (if you inject it). :) I'm not gonna waste my CO2.

[Squawkbert]

Ah - but CO2 addition does displace O2, and everything else according to whatever molar fraction of each constituent was dissolved in the water.

A given unit of tank water at a given temperature can have only so much gas dissolved in it. Adding CO2 to a saturated water column will drive off other gasses.

[Mgamer20o0]

MG probably means that CO2 doesn't displace O2.
yes thats it.



A given unit of tank water at a given temperature can have only so much gas dissolved in it. Adding CO2 to a saturated water column will drive off other gasses.
yes but it take a lot of co2 to get to the level where its driving out other gas. i am not saying you cant, i have done it, but unless your being stupid you shouldnt have to worry.

[ScottyNorq]

Well my plants grow fine with a basic strip light, no ferts or co2 injection. I have a few airstones but just because i like the bubbles.

[jmhart]

Ah - but CO2 addition does displace O2, and everything else according to whatever molar fraction of each constituent was dissolved in the water.

A given unit of tank water at a given temperature can have only so much gas dissolved in it. Adding CO2 to a saturated water column will drive off other gasses.


At the levels we are dealing with(or, at least should be), o2 and co2 saturation are independent of each other. Same goes for co2/o2 diffusion rates, independent at these levels.

[nickmcmechan]

i put o2 in one side and co2 in the opposite

there is a central bar across the tank and i raise the water level to the bar to spilt the surface, i have one agitated 02 side and another still co2 side...that side also has floating plants to keep the co2 in

i have an o2 test kit, found that 02 levels too low in this tank which is why i now run an airstone

[mphunk]

i put o2 in one side and co2 in the opposite

there is a central bar across the tank and i raise the water level to the bar to spilt the surface, i have one agitated 02 side and another still co2 side...that side also has floating plants to keep the co2 in

i have an o2 test kit, found that 02 levels too low in this tank which is why i now run an airstone

Have you seen any difference in your tank (animals, algae, plants, etc)?

I just had to ask this question. I know C02 and o2 are independent, yet still intricate parts of plant respiration. It was just rattling my mind why my o2 was so low. With all of us we try to minimize surface agitation to not off-gas our precious co2, yet unless we are adding an airstone or powerhead....the only o2 is from the plants and the fish/animals which utilize 02....:wall: