Good vs Bad anaerobic zones

[marcandkelly]

I asked this question a few days ago as a reply to some elses post. The original post had to do with powerheads and dead zones. Since the original post has been lost in server upgrade land, I am going to ask again...
Why are some anaerobic zones good (such as those in a DSB or LR) and some are bad (subtrate surface).
Thanks in advanced,
Marc

 

[wamp]

Anaerobic bacteria are responsible for the breakdown of nitrates. Without these places the bacteria would not grow thus not allowing the tank to get rid of nitrates.
Even in "dead zones" in a tanks water colum there is still oxygen. It is important to have power heads so water does not get stagnet in these places allowing algea and cyno to grow.
You need some areas of very little to no flow but usually that is in the rock or in the sand, not in the water column.

 

[marcandkelly]

I still don't understand why. Do different types of bacteria grow in these different areas? Or is too much of a good thing is bad?
I understand the breaking down of the nitrate and the importance of that. I don't understand why it maters where the oxygen depleted zones are located. <img src="graemlins//confused.gif" border="0" alt="[confused]" />
What does the nitrate break down to anyway? My chem teachers would be so disappointed in me .

 

[marcandkelly]

OK, now I get it. Thanks for the clarification Anthem.