Oxygen And Plants

[robbie carrobie]

hi, i read somewhere that if one over oxygenates ones aquarium that this can have a detrimental effect on plants. As i am about to embark on planting my 450 litre aquarium, which will be set up in a relatively low light/low tech fashion, i was wondering if anyone can provide me with any advise on the subject. reason is that i would like some airstone features and was wondering if during the process of oxygenation that this would reduce the carbon in the water and have a detrimental effect. I apologise in advance for any inaccuracies of statement, we all started somewhere - kind regards in advance - robert.

 

[Colin_T]

Water will only hold a certain amount of dissolved gases including oxygen (O2), carbon dioxide (CO2) & nitrogen (N). If you aerate the water the surface turbulence created by the airstone will help to maximise the oxygen levels and lower the CO2. Having said that there will still be CO2 in the water and you will never get rid of all of it. It is naturally in the air and is produced by the fish and filter bacteria.
At night when it's dark the plants will use oxygen and release CO2. During the day when they have light they will use CO2 and release oxygen.
If there is lots of light & fertiliser for the plants then you can add CO2 to get the best results from the plants. If you do add extra CO2 then it is recommended that you minimise surface turbulence to prevent the CO2 from being pushed out of the tank too quickly.
In low light you do not have to worry about CO2 and you can have an airstone or air curtain bubbling away all the time.

 

[robbie carrobie]

thanks so much, very helpful Colin, i planned to put the airstone on a timer anyhow just to minimise any chance that the co2 may get pushed aside quickly, kind regards and thanks again Robert.