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It occurs to me that opinions on the effectiveness of these products (and other bacterial cultures) is a subject of some controversy and disagreement...

I am very interested to hear what people think.

Anywayz, this is how I see it - does anyone else have a viewpoint - in agreement or opposing? Why or why not? I'd really like to figure this one out personally (I'm 2yrs into a BioMedSci degree in Microbiology, so I'm very curious on a 'professional' level.)

My view:

Personally, I don't believe they represent a viable long term solution, that they don't introduce viable species, and that they don't introduce them in nearly the concentrations that the manufacturers claim.

In terms of their long term viability, I don't find it credible that the same species that would survive in a sealed, bottled environment would thrive and survive long term in an aquarium - a common theme in many efforts using bacteria to control an environmental factor is that the bacteria are not perfectly suited to the environment in question, and thus die off.

In terms of the bottling itself, microbial growth kinetics and patterns would dictate that the population would be minimal.. First of all, in any aquatic system, bacteria prefer to form biofilms on the surfaces available to them, while in the bottle they are unable to do this, instead forming flocs, and increasing the turbidity of the solution. Secondly, any colony of bacteria would experience a sharp spike in population (exponential phase), followed by a levelling off (stationary phase) and finally a sharp decline (death phase) - after a relatively short period of time, any bottle of bacterial culture would contain relatively few living, viable bacteria because it would contain a huge amount of bacterial waste (often toxic to the bacterial species that produced it), and severely depleted nutrient stocks.



Last edited by geesloper at 14-Feb-2005 23:44

Hi,

You might find the next article interesting, especially the last bit titled Which Bacteria?

I know that Biospira contains these new bacterias, and that they are sold chilled to preserve them. I have never used it myself as it's not available in the UK, but there are posts around here of people who have used it who claim it worked wonders, i.e. cycled the tank instantly, so maybe that has something to do with it too.

The chilled stuff isn't available here, either, but I suspect it might work better.