# Cyanobacteria - work in progress



## maboleth (30 Mar 2017)

My 250l tank's been suffering from this algae/bacteria for at least 6 months. I tried every single recommendation I've found but with no results.

*I tried:*
_
- Increasing the water flow from 800l/h to 1200l/h. It didn't help at all. In fact, Cyano happily grows in areas that have the most flow.

- Extensively vacuuming the gravel. While certainly better for the whole tank, didn't even make a dent.

- Cleaning the filter from the excessive debris. Better for overall tank health, but no use for Cyano.

- Increased nitrates and lowered phosphates. Nitrate levels were 10-15mg/l with phosphates being 0,25-0,5. By Redfield ratio chart I was way into the GSA territory. But in reality, none of GSA was there, slowing Cyano only a little bit, if at all.

- Added more fast growing plants like Ceratophyllum, Ludwigia & Rotala. Great for tank, zero for Cyano.

- Easylife Blue Exit. Absolutely worthless. Nothing happened. It's basically a salicylic ac__id and aloe vera. Don't know what were they thinking, but no use._
*
What temporarily helped:*

_- Physically removing the patches of the Cyano. It helped the overall look of the tank, but required almost a daily maintenance of the gravel and glass walls._

So now I'm finally using the last resort: Erythromycin. I dosed slightly more than 2,5mg/l and will see how this goes. I will report here as the days go by. My plan is to dose the antibiotic for 7 days.


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## maboleth (1 Apr 2017)

Third day is almost gone... I still don't know what to think. I see some torn Cyanobacteria floating freely in the water, but majority is still green and on the rocks and gravel. I'm hoping the 4th day will finally kill it, otherwise I will raise the dosage.

All fish, inverts & plants look normal.


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## Shinobi (2 Apr 2017)

Why dont you try a blackout? Heard it should be quite effective against Cyano


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## maboleth (2 Apr 2017)

Oh, I forgot to mention that I tried a 3 day blackout. Yes it does work.

However, it stuns the plants and is only a temporary solution. Cyano grows back very quickly. The reason is simple - the root cause remains unfixed.
Antibiotics work in the similar way, however, all plants remain healthy and with CO2 grow in full force. 

So my goal is to kill Cyano with antibiotic while maintaining the full and rapid growth of my plants.So after the course finishes, I hope the plants will take the nutrients that were previously available to Cyano so it will be harder for it to grow back.


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## maboleth (3 Apr 2017)

Erythromycin was claimed to be a safe antibiotic for bio-filter because nitrosomonas bacteria are gram-negative and this antibiotic targets mostly gram-positive bacteria.

Funny thing is, Cyanobacteria is also gram-negative! No wonder there was almost NO visible action on my Cyano culture on the rocks and gravel with this antibiotic. It's the end of the 4th day and most of this algae remains green. I wonder if the treatment with Erythromycin was a myth? I will add the 5th dose tomorrow and if nothing happens I will quit this and use aggressive mechanical removals and heavy planting instead.


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## rebel (3 Apr 2017)

Try chemiclean. It generally works. But increase your erythromycin first though.


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## maboleth (4 Apr 2017)

Thanks, but there's no Chemiclean where live.

Fifth day ended and the effectiveness of Erythromycin was marginal at best, even with +1/3 higher dose of the last two days. My conclusion is that either Erythromycin is not effective at all (because it targets gram-poistive and not gram-negative bacteria (such as Cyano) ) OR there are many many Cyano varieties and not all reacting good to this antibiotic.

Anyway, my recommendation would be to collect some Cyanobacteria from the aquarium first, place it in a petri dish or any small container with water and add a small part of Erythromycin powder directly on it. If the bacteria reacts it will vanish, if not - it's not effective, thus no use to stress the whole tank.

Today I'm ending this treatment. All plants, inverts and fish are good so that's encouraging. I will do 50% water change, manually remove Cyano as much as possible.
I also removed one t5 bulb from the set, so now I'm at 78W (previously 117W). A bit low lighting for 250l, but the plan is to hit the Cyano where it hurts the most while keeping the plant mass bigger. I also bought some more Ludwigia and one Echinodorus ozelot plants.


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## micheljq (4 Apr 2017)

0,25 - 0,5 ppm of phosphates is not much, my plants stuggle at those levels.  Cyano can come from some kind of pollution, in my case it was rotting wood.

Michel.


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## maboleth (4 Apr 2017)

Not my case though, all plants are good, though I have no demanding plants aside from Rotala macrandra, which is doing just fine. Lost a bit of deep red hue due to decreased lighting.
While my tank is almost 4 years old, the gravel is more or less clear and all of the hardscape is new, only 8-9 months old.

So far so good though, I siphoned and removed as much Cyano as I could. No visible junk now. Overall my tank has less algae. One possibility is that plants are now more lush and healthy due to ferts & CO2. I also introduced 5 SAEs, few Danube Neritas and Malaysian trumpet snails. The cleaning crew. So it should be good. Keeping my fingers crossed.


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## Progen (16 Apr 2017)

http://www.theplantedtank.co.uk/algae.htm

Seen this yet?

The danger with using antibiotics in a tank is that is difficult to assess the exposure to the bacteria and you might end up making it harder to kill in the end.


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