Anaerobic substrate

[mandz]

Hi, can anyone kindly explain to me what it means when the substrate has become anaerobic? thanks.

[hwchoy]

that means if you poke a stick or pincer into the substrate, pulls it out and sniff, the memory of SAF night exercises wading through swamps comes flooding back.

Or if you don't serve, the effect is similar to kissing someone who just slept for ten hours and hasn't brushed yet

[xxdivinityxx]

What are the effects / drawbacks of the A/M condition of soil?
How do we prevent / 'cure' this

[mandz]

[quote:bedfaf486c="hwchoy"]that means if you poke a stick or pincer into the substrate, pulls it out and sniff, the memory of SAF night exercises wading through swamps comes flooding back.

Or if you don't serve, the effect is similar to kissing someone who just slept for ten hours and hasn't brushed yet [/quote:bedfaf486c]


hi choy, thanks for describing.... think i know how that smells....

i'm thinking of the same thing as divinity.... how do we solve it?

[Avenger]

as far as i know. you shudnt be solving it. by the time it happens to you its real real bad. its sulphuric acid released i think. i think can prevent be stirring gravel. hope someone can clarify better

[limsteel]

I have read 3 concept about this, which is really bery confusing to me! this is what I got... In places, (under the gravel) where OXYGEN lack or ZERO! the usual bacteria will not survive and other bacteria will form...

3 situation:

1. Bacteria will reverse the Nitrocycle and convert NO3 to NH4 to get the oxygen they need! read from a library book when I was browsing around...

2. Bacteria Break down the NO3 to N2 to get the Oxygen they need and form Nitrogen. It will then Bubble off in the atmosphere! (BEST DEAL)
http://www.drhelm.com/aquarium/substrate.html

3. In large quantities, anaerobic bacteria are bad because some types produce hydrogen sulfide as a metabolic byproduct. Hydrogen sulfide smells like rotten eggs.
extracted from: http://www.geocities.com/josh_shilling/bacteria.html

Hydrogen sulfide is formed by sulfur bacteria that may occur naturally in water. These bacteria use the sulfur in decaying plants, rocks, or soil as their food or energy source and as a by-product produce hydrogen sulfide. The sulfur bacteria do not cause disease, but their presence in water can cause a bad taste or odor.
extracted from: http://ohioline.osu.edu/aex-fact/0319.html


So now, which is which???

[loupgarou]

hydrogen sulfide doesn't cause disease but it IS TOXIC.

ok: the point with substrates. you want a reducing environment (ie: low in oxygen), but you don't want it to produce hydrogen sulfide.

[JLudwig]

[quote:55b9b0d04d="loupgarou"]ok: the point with substrates. you want a reducing environment (ie: low in oxygen), but you don't want it to produce hydrogen sulfide.[/quote:55b9b0d04d]

This is correct, you want it halfway in between plain gravel and totally rotting. In areas without oxygen lots of good stuff for plants happen, as01 you mention NO3->NH3 or N2 I believe which product is prefered has a lot to do with pH, I need to read about this some more. Plants like NH3 (higher in energy than NO3), and as long as roots can take the minor production in this can be a very good thing, providing a rich high energy form of N to the roots and keep the water column with the 'low energy' nitrate version of nitrogen. Algae don't have roots so you need to keep it in the substrate, a deep layer of gravel is needed for this...

Also at a lower redox potential than nitrate reducers you get the iron reducers, this is really good stuff it basically makes the iron present as a mineral in your substrate available to the plant roots. Plants are found in anaerobic soils in nature, this is the way they were designed to get iron... the survive by creating an oxyen rich area immediately around the roots...

But you can overdo it if there is too much organic matter in the lower substrate, so much that the roots cannot live... this is why a few handfuls/_thin_ layer of peat in the substrate is good, and a substrate made completely out of organic matter is bad. Just like a biofilter you can add lots of surface area to encourage these bacteria, all of this is cheap and easy and really can only help as you are making an artifical soil. Adding mulm to the base layer of substrate is an excellent way to get this bacterial colony going, I think Amano's Bacter 100 and Powersand are designed to do just what I described... If we think about it just like our oxygen-loving biofilters and take a few steps to encourage our substrate to be alive I would think the entire tank will benefit.

Hope that helps,
Jeff