# Oxygen



## bugs (26 Jun 2008)

I know it has been said before but I think it sometimes get lost with all the emphasis on preserving CO2, however, in my semi-lowtech* I've noticed the plants were in decline. Had been for some time but, given that I'm planning to do a new tank, I was inclined to leave it to see what happened over time. Time passed... and the beginnings of some surface scum made me decide to drop the lily pipe (heffer of a ugly plastic thing) and direct the flow to increase surface movement and increase oxygen exchange.

Anywaaaaay... The plants have picked up. The surface scum was minor so I'm reasonably satisfied that the "extra" light is not making the difference. That leaves me to conclude the oxygen was depleted. So, I'm losing CO2, gaining oxygen, and improved plant growth.

All un-scientific...


* Removed CO2 and 3rd tube from a high-tech.


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## Matt Holbrook-Bull (26 Jun 2008)

the surface scum disappearing when you increased surface agitation is probably more due to the fact that the surface was more violent, so the wastes were forced back into the water, and therefore caught by the filter   I doubt it had anything to do with more O2.


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## bugs (26 Jun 2008)

Matt Holbrook-Bull said:
			
		

> the surface scum disappearing when you increased surface agitation is probably more due to the fact that the surface was more violent, so the wastes were forced back into the water, and therefore caught by the filter   I doubt it had anything to do with more O2.



Erm... I was not attributing the disappearance of the scum to more O2. In fact the relevance of the scum is largely immaterial except to explain what prompted me to meddle with the flow when I had previously been pragmatic.


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