View Full Version : Cyanobacteria: Beginning to End

10-09-2008, 06:17 PM
It has been about a year battling a nasty algea in my aquarium. A year ago, I noticed a nasty green slime covering my newly bought plants in my tank, so being new to it, i reached for some Algea Destroyer Advanced, thinking, "This will be gone in a week", and here I am a year later (and a year smarter) doing biological research and developing an extensive plan of action.

At one point in time, I performed an experiment on ADA's effect on cyanobacteria, and the simple result was this: It works very well on initial control, but long term use is expensive, and does not work. The I just cleaned out the test bowl a week ago, full of cyanobacteria.

I have found in my early research that "Blue Green Algea" is not an algea, but a bacteria known as cyanobacteria. In later research, i found that the anti-biotic erythromycin is cyanobacterias worst enemy. More research indicated what I hypothesized was correct: Using the erythromycin would create a huge cyanobacteria die-off, a huge release of protien once used by the bacteria cells are released in the water upsetting the balance of the water chemistry. This protien is broken down into either ammonia (NH3), nitrites (NO2) or nitrates (NO3), so these three parameters will be of particular interest to analyze the behind-the-scenes activity in my affected tank.

Now, you may be thinking that using erythromycin in your tank will destroy your biological filter along with the cyanobacteria. This is where looking at and comparing nitrobacter, nitrosomonas, and cyanobacteria is important.
In doing this we notice that they are all gram negative, not suceptable to moderate amounts of erytromycin. However, I must not leave out that cyanobacteria being gram negative, is also a distant relative of the gram positive families. This means that it is sensitive to erythromycin, making it an effective weapon against the nusiance cyanobacteria, without putting your valued biological filter at risk, when using the anti-biotics as directed. And noting the use of the antibiotic, I must stress the importance of using erythromycin for a while after all of the cyanobacteria is gone, because when you think it is all gone, you may not see the last of it hiding in a corner somewhere. In that case, you will develop an aitibiotic-resistant strain of the cyanobacteria in your tank, and good luck is all I can wish you then. Also, erythromycin has no effect on your fish or plants, so extended use has no ill effects. However, I cannot say this about any other living organism you may have in your tank, as I have not researched this myself.

I will be looking into treating cyanobacteria for some more time here, and will be posting more of my findings here when they become availiable.

I can definitely say that Aquarium Biology is very interesting, and can help me find out about the behind the scenes story of my tanks, but also help provide ways to understand the source of the problem and how to correct it.

If there are any questions or comments you have about my findings, I am excited to know what they are and I will try to find an answer.


10-09-2008, 06:47 PM
My understanding is that the quickest way to remove or get rid of cyanobacteria (at least for freshwater) that you simply increase the lighting period and physically removal via siphon. Was that a method you did not test, or you tested it and found the other methods better or more efficient?

10-09-2008, 07:02 PM
I should specify that my tank is a 20H Gallon Freshwater Tank, thank you for pointing that out Fins n Fur, and I apologize.

I have been scraping the algea off and siphoning out the remains with a Python No Spill Clean 'n Fill for about a year now. In my case, this does not seem to be an effective method, and as I have stated before, Algecides were used back when the problem first occured, but as I found out that it was harmful using algecide, I quickly scrapped that idea and do not reccomend that method to others. Also an experiment I performed showed that the algecide had only temporary effects on it, and the cyanobacteria re-appeared.

In response to your question, no, this isn't working for me right now and I am studying the biological approach to plan a new way to get rid of the algea (no, I am not coining the use of anti-biotics, it is just new in my experience)

I do not understand what you are asking about the lighting of the tank, but assuming you mean to reduce the lighting, I will say that my lights are on for 15 hours a day, and will be reduced to 10 this weekend. So, yes, I think my lighting is off balance, so correcting that I think will play an important role in controlling the cyanobacteria outbreak.

Thank you Fins 'n Fur for your question as it brought about another important aspect to this post. I look forwart to your future contributions not only for the education of others, but that of my own as well.

10-09-2008, 07:11 PM
When I had a freshwater tank and had the cyano problem I found frequent water changes and Algone helped take it out quite quickly. You might try that out if you're ok with experimenting. What are your water parameters looking like?

10-09-2008, 08:02 PM
Thank you oldhead for your input.

I mentioned in my first post on this thread that I used API Algea Destroyer Advanced. Both that and Algone are both algecides, and reading the ill effects it has on plants and fish, and the fact that it is only a temporary fix, I am hesitant to use it. However, I am not against having a look at whats inside Algone.

My position on algecides is this: Its only a temporary fix for a solution, and does not get to the underlying cause of the problem that results in cyanobacteria. Knowing that, why add any more chemical to the tank then needed?

My parameters are as follows:
pH: 7.6
NH3: 0
NO2: 0
NO3: 0

I am looking into getting additional test kits before I begin using antibiotics in my aquarium to monitor more parameters throughout the adventure.

I have read that cyanobacteria thrives where NO2 is at the extremes, being low and high. As of right now, I would have to guess that improper lighting and low NO2 is responsible for the outbreak, but I need to test other parameters before I come to a solid conclusion.

I am interested in hearing more about your battle with the cyanobacteria using Algone and your water change schedule. Would you mind posting more details about what you did, and if it came back how long if at all?

10-09-2008, 08:26 PM
You haven't mentioned in your poll one way that works very well and is a good long term solution. When if first started to show up in my 125 planted tank, the first thing I checked was my parameters and I found them to be exactly as yours are. Simple solution, I started an active fert dosing program that included NO3. I maintained my NO3 levels at 5ppm and I never had a problem with BGA after that. You are correct in the statement that Cyanobacteria thrives when NO3 is 0 and if you are maintaining a planted tank, this is when you will find it most frequently. NO3 dosing is probably the best longterm solution since your plants need the NO3 anyway. It's probably the cheapest and safest method as well. If you can find dry ferts, your dosing is just pennies a week.

10-09-2008, 09:03 PM
In response to ILuvMyGoldBarb, I apologize for that, as I was just toying with the poll a bit, its the first I made, and it was kind of just for kicks.

In this tank, I dose K20 and Fe. In otherwords, Potash and Iron. I have not yet dosed any NO3, and I am pleased now that there is someone else that can confirm that low NO3 is a suitable environment for cyanobacteria. So now, I am thinking that I should use erythromycin to destroy the cyanobacteria, and after it has been destroyed, begin dosing NO3. Also, I have read that cyanobacteria does not do well in acidic waters (low pH), and I am guessing that the pH of 7.6 in my tanks do not help the situation any. I have C02 injection with a small, natural yeast on sugar unit. I plan on getting a pressurized system for use with the tank. Using that to my understanding, can help lower pH, and thats one less positive in my tank for the cyanobacteria.

10-09-2008, 09:20 PM
The erythromycin is not necessary. If you simply start dosing with NO3 the cyano no longer has an environment that is conducive to it's growth, once that happens it will go away. Don't treat the symptom, treat the root problem and the symptom will go away on it's own.

10-09-2008, 09:30 PM
It was reccommended to me to increase the lighting on my 2.5 with a cyanobacteria problem (have you read Dave66's algae primer?) It's only been a week so I can't report much, but thought I'd throw that out there.

10-09-2008, 09:37 PM
Let me clarify invader toast, that I just bought a coralife freshwater aqualight 64 watt for a 20 gallon tank.

That is over 3 watts per gallon.

So I think the remaining two factors in my battle is adjusting my fertilizing and beefing up my C02.

*Update: I am almost done with a blackout cycle, and it has the cyanobacteria dead at the moment, we will see how long it takes for it to come back.

10-09-2008, 09:38 PM
The increased lighting is great if you have an excess of nitrate but not so if you have 0 nitrate. I tried that method when I had 0 nitrate and my tank ended up worse than when I started.

10-09-2008, 09:56 PM
Good to know. Now that I blacked my tank out, the cyanobacteria died, but i cant find any powdered NO3.

Antibiotics is a last resort.

10-09-2008, 10:39 PM
Also, CO2 and cyanobacteria would be a good thing to discuss as well. I hope to do some research on that to learn more about its role in keeping cyanobacteria in check.

10-09-2008, 10:41 PM
And I keep forgetting to ask two things, where do you buy powdered NO3? I cannot find any online. And how do I edit posts so I dont have to make a whole bunch of little ones when I forget to ask something?

10-09-2008, 11:44 PM
I usually comes as KNO3, that is the easiest way to buy it.

The addition of CO2 is often a contributing to the development of cyano because people will add it and not be aggressive enough with their dosing. There is an unfortunate line of thought out there that leads to higher and higher lighting. When the unfortunate planted tank hobbyist hits about the max they can, they find out they should be using CO2 to facilitate the uptake of the nutrients to get rid of the algae they have. They add the CO2 and in a short time there is no NO3 left in the tank and the Cyano breaks out. Planted tanks are all about the balance of nutrients, light, and CO2

10-10-2008, 08:28 AM
And I keep forgetting to ask two things, where do you buy powdered NO3? I cannot find any online. And how do I edit posts so I dont have to make a whole bunch of little ones when I forget to ask something?

To get you started, you might do a google search on the estimative dosing methoed of fertilizers (Note that there are other methods). Planted tank forums are another place to look to where's best to buy not only Potassium nitrate, but other dry ferts you are looking for. Rex Grigg (www.rexgrigg.com (http://www.rexgrigg.com)) sells dry ferts.

11-15-2008, 07:41 PM
Its been a while...

I have been continuing research, and today marks the fourth day in my Erythromycin treatment. Here is what has happened so far:

Day 1 - I cleaned the tank up very thoroughly making sure to get rid of most to the cyanobacteria. The plants were placed in postions that I wanted them to remain for a long period of time. I dosed the first treatment and ofcourse, there was no real noticeable change in the remaining cyanobacteria from the plants.

Day 2 - Second dose goes in. The cyanobacteria is not reproducing nearly as rapidly as it has in the past.

Day 3 - Third dose goes in. Small colonies are appearing in places, but over all, it is not a widespread issue in the tank. I did a water change today and while doing so, i discovered some spots where grey (dead) cyanobacteria have been acumulating.

Day 4 - I am at work typing this post, and away from my aquarium untill day 5, so I will not have an update for this untill later tomorrow.

At this point, My plans are to begin dosing fertilizers according to the Seachem dosing guide at www.seachem.com, on Day 6. Day 6 marks the last day of the treatment, but it is my guess that I will have to continue to add erythromycin for a second treatment period to fully kill the cyanobacteria to prevent buildup of EM Resistant strains from growing. I will go from a once a week water change to a waterchange every 3 days. By this plan, I am hoping to create an environment where the plants can out-live the algea, and therefore remove nutrients before the algea can get to it.

11-17-2008, 10:04 PM
I am happy to report that the number of colonies of cyanobacteria growing on my tank are now reduced enough that I can count them all on one hand. However, as the first full treatment of Erythromycin is over as of yesterday, I will continue to treat the tank for an additional treatment (5 days). Also I have started dosing Seachems full line of fertilizer to my tank to help the plants get an edge on the cyanobacteria. The current plants in the tank are 2 very very small amazon swords (they will be working their way into my 65 gallon tank when I purchase it this coming summer) vals, red ludwiga, micro sword, moneywort, baby tears, elodea, unidentified lilly pads, and camboba. The babytears, ludwiga, microsword, and moneywort have only been in the tank for a week, and now they are rooting rather nicely, and the new additions are a playground for the ghost shrimp. Looking at my fertilizer chart, I will change my water change schedule back to once a week, so I do not end up creating an imbalance in the fertilizer supply, therefore creating an invitation for cyanobacteria to come right back. During this week I hope to make a few reports on how things are going, and hopefully in 5 days, I will be cyanobacteria free, and let the plants, lighting, co2, and fertilizers prevent its return. Also, another important factor will be the weekly water change!

11-18-2008, 01:12 AM
Very interesting experiment you are doing there. I'm looking forward to hearing about the results. The key will be to try and keep everything in balance once the cyano is gone to prevent it from returning. About the co2, I noticed that when my DIY co2 starts to slow down, I start getting an increase in algae. Once I get it going good again, the algae starts to die off. (zfish)

12-31-2008, 08:14 PM
so i doubt i can get my dr. to give me a scrip for antibiotics, where could i get my hands on erythromycin?

01-02-2009, 03:59 AM
The best value I found is ordering Erythromycin from BigAlsOnline.com. Search for Erythromycin and select the one manufactured by API. For my 20 gallon tank, it took 2 boxes. I would get at least one extra box, it is rather inexpensive. Also make sure that you have the proper lighting, fertilizer dosages, and CO2 addition to your tank during your treatment. This will make cyanobacteria almost disappear for good in your tank.

I reccomend the full line of Seachem Flourish fertilizers, also sold on Big Als Online. The full line consists of:

Flourish Excel
Flourish Nitrogen
Flourish Potassium
Flourish Phosphorus
Flourish Iron
Flourish Trace

Lighting is also important. It comes at a bit of a price, but the light is not the top of the line product, but will serve nearly the quality of the expensive ones. Search for coralife aqualight, get the proper size, and also make the small investment in the Aqualight Deluxe Mounting Legs, these make the fixture hover about an inch and a half over the surface of the water and it flips up out of the way for very convienient cleaning.

CO2, you can go a few routes. I reccomend getting a system that produces air bubbles, not fizzing tabs. You can get a cheap set of fermentation units for 30 dollars tops and for about 20 dollars a year it keeps going. I am not sure about pro units, as I do not use one, but for larger tanks, this will be the way to go. Fermentation units are great for tanks 20 gallons or less. The 65 gallon I plan on getting will be orderd along with a pro CO2 system.

The best thing you can do is ask questions and do research, never buy on impulse, if I did, i surely would not have the nice set up I do today.

:goldfish: Good Luck:fish: