Understanding the plant / oxygen relationship

[tim_s]

Hi,

When removing all surface agitation from the aquarium to prevent gassing, what is the method of understanding whether your plants have the capacity to supply oxygen to the live stock that exist within the tank?

Bare in mind my tank is sitting at 82F to house discus.

 

[jlk]

I believe when your tank is at maximum saturated oxygen content for the temp of your tank, you will see your plants 'pearling' (little oxygen bubbles forming on the leaves) because no further oxygen can be dissolved in the water. This would indicate your plants are doing their job. Someone please correct me if I am mistaken!

 

[tim_s]

Absolutely! My concern is I am making adjustments in the mornings so that the tank goes through a light cycle I have removed as much water agitation as possible to prevent gassing.

I am concerned that if the plants are in poor condition and I have removed all noticeable forms of surface agitation that the end result will be poor oxygenation within the tank.

This might be an irrelevant concern being I have over-flows to a sump.

 

[jlk]

I have no experience with sumps or running co2 systems, so I am afraid I dont know the answer here. My suggestion would be to watch your fish's behavior for signs that theres a lack of sufficent oxygen. Gasping at the surface, heavy breathing and/or erratic swimming behaviors are all indicative that there may be an issue with sufficent oxygenation that may need to be addressed. Hopefully, others with more co2/sump experience can provide some input!

 

[bigbanker]

This might be an irrelevant concern being I have over-flows to a sump.

Pretty much spot on!

 

[tim_s]

I figured as much!

 

[aqua_chem]

The 'minimum surface agitation to prevent off-gasing' concept is most applicable in DIY CO2 circumstances. In this scenario, the maximum output of CO2 is severely limited by biological factors (ie, the yeast). With pressurized co2, you can increase CO2 throughput (high bps) to compensate for off-gassing. As long as the surface disturbance is kept to a reasonable level (no splashing, etc), you can have the best of both words.


As an additional concern, all gases have reduced water solubility in hotter temperatures, so this becomes even more important.

 

[Link119]

If you turn the temp down of your tank, there is going to be more oxygen and CO2 in the water so your fish and plants have a larger gas supply.

 

[aqua_chem]

If you turn the temp down of your tank, there is going to be more oxygen and CO2 in the water so your fish and plants have a larger gas supply.

That's not really an option with Discus though.

 

[tim_s]

That's not really an option with Discus though.

Correct! - This has been amazing help!