mojoreef said:
What advantages??
Well first, whether they are an advantage or not, many of us have them so it is important to deal with them.
Second, I would suggest that a DSB can help to provide biodiversity in the system that is advantageous for a number of reasons, one of which allowing a higher bio-load into the system and for use in a refugium as a place to provide a source of food for corals and such.
opps I guess this answered the above thought. Collin alot more then I think you could imagine.
Well, I'm sure you are right, however, I can imagine a lot.
I talked to one of our resident microbiologists yesterday in the biotech dept. About 7 years ago, he and I spent quite some time on a project in which we had isolated and identified a naturally occuring lactone based by-product of a commerical manufacturing process. We intended to synthesize this material and scale it up for manufacture in our plants. This material had the ability to interfere with the molecular machinery that many bacteria use to produce the polysaccharide bio-film you are refering to below. These biofilms are a particular nuisance to our company as they provide the cell cultures growing in our customers water chiller units a shield against our biocides. These bio-films make it difficult for our biocides to kill the bacteria as economically as we would like and can cause a number of other problems. The project ultimately failed for a number of economic reasons, none of which related to the efficacy of the drug. However, during the time I learned quite a lot about bacteria cultures and biocides.
The vast majority of bacteria dont live on the surface area as much as they live in the biofilm and biproduct of what they produce in order to reduce. You cant look at a sand bed as clean sand with bacteria living on the surfaces. You have to look at it like one complete mass of goo with sand in it. The goo being a mixture of everything from bioflim to byproducts to waste to chemicals of all natures. So growth will be limited by enviroment, and surface area will play a part but is not all emcompassing. A clump of waste on top of the sand can house the same ammount of bacteria that the equal clump of sand would.
mike
I'm sure this is quite accurate.
I asked my microbiologist friend yesterday about limits on bacterial populations imposed by space. He said that yes, there certainly were limits. He then showed me some cultures he had growing that exhibited this phenomenon. According to him, when the cultures reach a limit for space in thier substrate, they will be pushed upwards into more oxygen rich environments in which they will die. Of course this happens in a series of cycles as we know. However, in the end, they become limited. At that point, in order to avoid the oxygen rich environment, they will start to overcrowd. Their own waste materials will then begin to limit their populations. So basically the cells can build up on thier substrates and compete and act symbiotically with other less aerobic bacteria until there is no more room to grow. From here, the biofilm containing bacteria can either slough off the surface and try to find somewhere else to live, or that being unsuccessful, they will die off and/or be limited at that level when considering the entire population. From there the bacteria are no longer nutrient limited, but are instead space limited. After that, phosphate will move from a regime 3 type behavior to a regime 1 type behavior and P and other nutrients will begin to build in the water column and also by saturating the limestone itself according to their equilibria. Here is where the aquariast will begin to notice more chronic problems that may indicate in impending system crash unless something is done.
How can we stop this???
Sincerely...Collin