Re: Antibiotics usage

Hi Dionigi,

Thanks for the input. It sounds like you know something about this :-)

I forgot to mention one important comment in my dissertation on the use of
antibiotics for BG algae......--->  I do not generally recommend, them.... I
do not generally use them, .... except as a last resort! or when I am very
impatient :-)

But even then, I still use them at low doses.  "Maybe" I am taking the risk
of creating a resistant strain, but at the same time I am protecting the
other flora in the tank. As you indicate, with full dose antibiotic
treatment  "other beneficial bacteria (in the filter,on the fish mucosas,
etc.) are killed as well (sometimes more efficiently than the bad ones!)"
Also, to my knowledge, cyanobacteria are only "like" a bacteria. The doses
for mycins are based on disease producing strains of bacteria. Do you know
if there is variablity in the sensitivity of different bacteria to mycin
antibiotics.  Maybe 2.5 ppm is all that is needed to be effective for BG
algae ( * and see below).  I have rarely had to use more than 1 dose at
2.5ppm and I can only count 2 times that I used repeat dose... and this is
after a week. Consecutive daily doses may even be better, but I would think
that this depends on the how quickly the bacteria die. 

Low kill rates (99%) could still work... here is why.  I might only get 99%
kill the first day; then,  with second dose, I would get 0.99 % cumulative
kill. The remaining .01% is 1 thousandth of the population that I started
with and the other defenses in the aquarium can more easily take over.[Note:
I just used 99% as an illustration]. Maybe naive to say this, but I am not
worried about creating any resistant strains of cyanobacteria lurking in the
gravel, any more than the same BG cells could be lurking without mycin


(*On the other hand, if BG are supersensitive to mycins, then could it even
be better to treat at 1 ppm for several days. This is a question I cannot
answer. DO you know if this inforamation is known about BG algae.  Otherwise
some tests may be needed.)


Neil Frank, TAG editor    Aquatic Gardeners Association    Raleigh, NC USA