I found this a few days ago and thought it was just fantastic so I thought id share!

http://www.oscarfish.com/water/71-autotrophic-bacteria-manifesto.html

http://www.oscarfish.com/article-home/water/72-heterotrophic-bacteria.html

if anyone finds anything incorrect about this id love to know. anyway it helped me a lot with understanding the processes

love n peace

will

Good articles Will, thanks for sharing. 

 

I can't comment on Nitrospira vs Nitrobacter. That's at odds with my education but quite possibly correct. Our understanding of things changes constantly. I do want to suggest that there's little difference between the film of water supporting aerobic bacteria on a soil surface or a filter media surface, especially on a wet-dry type of filter. It's likely that both groups of bacteria are converting nitrite in both situations. 

 

I didn't read the article thoroughly but I'll try to get back to it. A couple of points worth going back to: 

Below pH 6 nitrification stops. The bacteria don't die they just become inactive - presumably they cannot survive in this condition indefinitely, they will starve. That's what I was taught too. In fact I recall an equation that showed the process running backwards at very low pH, ie Nitrate being converted back to Ammonia. I've not witnessed the process running backwards (yet!) and think nitrification doesn't actually stop at pH 6, it just slows to a virtual stop. I can't understand how or why anybody chooses to run a tank (think Taiwan Bees) at a pH below 6, and am not surprised such animals are prone to dying when moved elsewhere. In those conditions the animals have effectively never been exposed to bacteria and have absolutely no acquired immune defences. My taiwan bees are at 6.4 and while I had some initial trouble with purchased stock, those bred in the system seem very tough. 

 

Oxygen demand - many people don't consider their aquarium microflora/fauna but it is the hungriest and most active organism in your tank. In much the same way as that there is more kilograms of ants than humans on this planet, more oxygen is consumed by your biofilter than all the other combined livestock in your tank. I remember many years ago visiting the fishroom of a very successful commercial breeder and being surprised by the lack of filtration in all tanks. All he had was bare airlines bubbling away. He said that filters just made more work, as the pH dropped away too fast when he used them. While I don't recommend that practice at all, he had some top fish there which are simply not available now that he's out of the game. Anyone who kept Apistos or Killifish probably knows who I'm talking about. 

 

Competitive exclusion - we deliberately add heterotrophic bacteria to shrimp systems as an immune stimulant. These non-pathogenic strains awaken an immune response in our shrimp while at the same time fill all the niches where pathogenic strains may have occurred. I am thinking about Mosura BT9 which I have, sometimes I even add it to the tanks! I have read plenty of reports of shrimpers having better results using standard aquarium products rather than shrimp-specific ones.