cyanobacteria & purmycin

Anybody have experience treating a tank with purmycin? I've got an outbreak of cyanobacteria, presumably from low nitrate levels and potentially ammonia at some beginning stages from the Aquasoil. I hear it's 200mg for 10 gallons (45 litres). Is that correct? Thanks

 

from my understanding, you can "cure" this by doing a black out! but not sure how as I haven't done it before.

 

Shot Sunny, thanks R.C.

Did some research and found that a blackout for 3 (better 4) days works best. So I'll do 4. Let's see what happens.

I realise now I made a critical mistake. When algae started appearing I backed off on dosing in the thought that less nutrients means less algae - WRONG. I should have maintained and would have had less, but probably still have had this BGA. Seems a very common thing to happen in new high tech tanks, never picked that up on this forum. I should have been dosing more nitrates for sure. I graciously offer myself up to the school of hard knocks.

 

Hi Adrian,

Here is a intense discussion on the topic:
http://www.tropicalaquarium.co.za/archive/index.php/t-2467.html

Of particular interest is this:"EM is gram positive. Nitrifying bacteria are gram negative. Cyanobacteria are also gram negative, but seems strangely sensitive to EM. There is hardly a fish dissease which can be treated with EM these days, so the use of this anti-biotic will not cause immune strains of anything in your tank."

 

I take any discussion from TASA with at least 10 kg's of salt Read that one already.

It's quite funny. Here, everyone was saying "dude you have too little light" when I was planning this tank, elsewhere, people are saying, "you have too much light"

 

Ok, how about this one:
[F/M]Blue-green algae and erythromycin, a summary. (long 8k)
by -at-Tony.Clementz.mikrbiol.lu.se (Tony Clementz)
Date: 7 Feb 92
Newsgroup: rec.aquaria
I've followed the postings about blue-green "algae"
and Maracyn (erythromycin) the last few weeks and the
following is an attempt to review some facts about
erythromycin (the active ingredient in Maracyn) and blue-green
algae, with special emphasise on the use of erythromycin for
treating blue-green "algae" infections.

BLUE-GREEN "ALGAE" IS NOT AN ALGAE.

Thats right. The correct name is blue-green bacteria
(or cyanobacteria for those latin freaks out there). So
without going into a lot of details, blue-green algae is a
bacteria so an outbreak of the stuff in your tank is actually
an infection.
It is important to know that blue-green bacteria
comprise a large and heterogeneus group of organisms. Not even
the color is the same. Some are green, some blue-green, and
some are red. They can be found almost everywhere in nature.
They are usually more tolerant to extreme environments than
"normal" algae and can be found in hot springs as well as
saline lakes. Drying your gravel and tank is subsequently not
an efficient way to get rid of them. Some species can even be
found in the middle of the dessert. Blue-green bacteria
efficiently absorbes light between 550-700 nm, which is
roughly the same as for plants and green algae.
As we all know, they thrive in warm water, rich in
nutrients. However, many blue-green bacteria is not dependent
on nitrite, nitrate, or ammonia, since they can use molecular
nitrogen (nitrogen fixation). This all leads to the well known
conclusion - once established in the tank, they are a pain in
%&#-%&. I wonder how many potential aquarium hobbyist has been
lost because their first tank became covered in green slime
within six month.

GRAM-NEGATIVE AND GRAM-POSITIVE BACTERIA.

Bacteria can be divided into two groups, either Gram-
negative (G-) or Gram-positive (G+). This classification is
based on if the bacteria stains (+) or not (-) in a special
staining technique - the Gram staining (invented by Christian
Gram). Positive or negative staining reaction reflects a
fundamental difference in the structure of the cell wall of
the bacteria.
ERYTHROMYCIN IS AN ANTIBIOTIC.
Erythromycin is more efficient towards G(+) bacteria
than G(-). It is one of the safest antibiotics, meaning that
it does not affect plants, fish or animals. Blue-green
bacteria belongs to the G(-) bacteria but it is a special case
with respect to sensitivity to antibiotics (i'm on thin ice
here, but I think I am correct). They are more sensitive to
erythromycin than other G(-) bacteria. Fortunately, the
bacteria important for the nitrogen cycle (your biofilter) are
of the G(-) type and are much less sensitive to erythromycin
than the blue-green bacteria. So your biological filter is
"fairly" safe.
The reason that some tanks experience an ammonia peak
after treatment with erythromycin is (probably) not because
the biological filter is non-functional. It is more likely
that it is because of the high content of protein released
from the dead blue-green bacteria which is broken down to
ammonia and/or nitrite by the "good" nitrifying bacteria in
your biofilter. This boost of protein to be broken down upsets
the finely tuned balance of different bacteria in your filter.
(Actually, if you killed of all bacteria in your tank and
filter, you would never get ammonia).
In many countries in Europe there are restrictions on
buying antibiotics. You usually need a prescription. I suggest
contacting a vet. If he can prescribe antibiotics for a mouse
I'm sure he can do the same for your tank. Remember, your tank
is infected.

WHAT NOT TO DO.

First a few things NOT to do (my own, very personal,
experience).

If you have an established infection, do not try to
get rid of it by turning the lights of. Most likely this will
get you into more trouble. Your going to kill of the "good"
algae and the plants, but the blue-green bacteria is going to
return when you turn the lights back on (usually more fiercly
than before).

Personally I don't like copper. Copper is poisonous to
everything - plants, fish, and bacteria. At least in Europe,
most "miracle" treatments you buy contains copper.

You could try manually removing the blue-green algae,
combined with extensive water changes. But in my experience
it's fruitless, unless you spend all your free time with your
fingers in the green slime. Ever tried to clean the stuff away
from Cabomba or Java fern? Then you know what I mean.

WHAT TO DO.

Of course, tank hygien is important. Regular water
changes and all that. But for those who has been doing it all
according to the textbook and still wondering if your doing
something wrong, don't despair, you have'nt been hit by a
blue-green curse.
Me myself, I get an infestation in about every second
tank (freshwater) I set up. These does not correlate to any
increase in ammonia, nitrite, or nitrate (I do not keep check
on phosphate, but I plan to). One exception is tanks with soft
and acid water. You rarely find blue-green bacteria in these
tanks since most bacteria, including blue-green, do not like
acid conditions.
The followin is my suggestion for battleing blue-green
algae:

First make sure that it is blue-green bacteria and not
the "normal" algae. Remember that erythromycin is ineffective
on anything but bacteria.

Day 1.
Add 2.5 Mg/L erythromycin. If you have a protein
skimmer, turn it off. I believe it will inactive a lot of the
antibiotic through coprecipitation with protein. It will,
however, be very usefull later.

Day 2.
Add 2.5 Mg/L erythromycin.

Day 3.
Now you should see a lot of dead blue-green bacteria
floating around in the tank. Increase filtration (a second
mechanical filter if possible) to get rid of it. If you have a
protein skimmer, turn it on. The critical thing now is to get
rid of as much protein (dead bacteria) as possible to avoid a
peak of ammonia.

Day 4.
Most blue-green bacteria should be dead by now. Try to
clean out as much as possible of the dead stuff. I use a jet
stream of water from the outlet of a canister filter to remove
it from plants and decorations. Combined with the second
mechanical filter, this works fine for me. Let the filter work
for a couple of hours then make a 50% water change. Add 2.5
Mg/L erythromycin.

Day 5-7.
Wash the mechanical filter at least once a day. Keep
check on ammonia and nitrite but do not change any water
unless absolutely necessary. The extra filter can be removed
as soon as the water clears up.

Day 8.
Make a 30% water change. Add 1 Mg/L erythromycin.

From now on, resume your normal maintenance.

The concentration I use is in theory a bit high and
getting up where it should starts having an effect also on G(-
) bacteria. When I started using erythromycin I had problems
using lower concentrations in the tank. It was not very
effective. It might be time to check it again.

One word of caution. Only use erythromycin when you
really need it or you might end up with blue-green bacteria
resistent to the antibiotic.

My practical experience of using erythromycin to
battle blue-green bacteria is limited to my own few tank (and
some friends). It would be interesting to get some feedback
from people with experience (good or bad) of battling blue-
green bacteria (with or whithout erythromycin). I would of
course post a summary of the response.
----------------------------------------------------------------------
Tony Clementz | Email: Tony.Clementz.mikrbiol.lu.se
Dept. of Microbiology | or
University of Lund | Internet: biogen6-at-gemini.ldc.lu.se
Solvegatan 21 | BITNET: BIOGEN6-at-SELDC52
S-223 62 Lund | Phone: +46 46 104451
SWEDEN | Fax: +46 46 15783

 

Thanks for the post, very interesting. What's also interesting is that he says do not do a blackout, but yet every single other source says the blackout is the only way... And he also says your filter is "fairly" safe What will be will be.

 

I've used Eurythromycin to treat Cyanobacteria a few times, with excellent results. I no longer use it, because I no longer have cyano. But I dosed one capsule per 100L of tank water. Following day, big water change. 2 days later dose again. Following day big water change. 2 days later dose again, and last big water change. It solved my issue very well.

 

Jip, in a case like this I tend to go with the Microbiology professor...?

 

Someone else was telling me this isn't cyano, but BBA. What do you guys think? It looks nothing like BBA to me!

I did 3 days worth of Eurythromycin, then a 60% water change and have wrapped the tank totally dark. Do you think I'll be in for a nasty surprise when I unwrap it Friday? Dead fish etc.? Or no change?

And, do you think 3 x 54 Watts T5's is too much for the tank? When I started it I was adamant 2 x 54 was enough, then later realised perhaps it wasn't. Now I'm confused

 

Sweet thanks. Will still do this blackout thing for 3 days then. Massive mistake I made by reducing ferts when I started seeing algae.... Do you think my lights are too much? According to me, I fall into the medium category. Unless I'm mistaken.

 

Okie dokes!

 

Shot! Opened it up now (I'm at home sick ) and will do a small water change and siphon off more rubbish.

 

Ive noticed that nobody has mentioned flow. I'm no expert but I had some BGA at some points but manually removed it then increased the flow of the filters and redirected the stream so it improved circulation to areas where there wasn't any and where I noticed the BGA was starting. As soon as I improved the flow it never returned.