Cyanobacteria - Tropical Fish Keeping - Aquarium fish care and resources
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post #1 of 5 Old 05-03-2009, 03:42 PM Thread Starter
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Exclamation Cyanobacteria

CYANOBACTERIA [sahy-uh-noh-bak-teer-ee-uh]: What I have found out about it, and the ways that I've found to deal with it.

First off, I had never heard of cyanobacteria, thought it was algae tried to rid the tank of it by cleaning everything. Looked great for a day or two, then it was back, cleaned again, looked good but guess what? A day or two later, it was back and growing even faster. I was just going nuts!! I went to several pet stores. They told me it was algae, that I was not cleaning my tank properly and that I must have bad water quality. Told me to use a product to rid tank of algae, it did nothing at all, not even to slow the growth. The rest of my tanks looked great and are in the same room. Get the same light, feed the same time everyday and none of them grew algae. So that didn't sound right to me ( I do keep a good eye on my water and test regularly ). I tested water for everything I could, kh, gh, phosphates, co2, ph, nitrites, ammonia, nitrates. The only thing that was even close to above normal was the nitrates, but all tanks were in the same range. Now I was really confused, pulling hair out! A friend of mine came over and noticed the tank and said it was cyanobacteria. The quest was on to find out what I could about cyanobacteria, and what was wrong with this tank, here's what I found.

A) What is Cyanobacteria in aquariums:
A unicellular aquatic and photosynthetic organism. Just waiting for the conditions in your tank to become just right, then it blooms. Cyanobacteria looks like algae, acts like algae but it is not algae. Cyanobacteria is one of the oldest bacteria known to man. Its fossils are thought to be more than 3 billion years old. They are most commonly known as blue-green or red-slime algae. They can be found in saltwater and freshwater aquariums, and have many different colors depending on the condition of the water. Brown, red, green, blue-green. Red and brown are most commonly found in saltwater tanks. Green and blue-green are most commonly found in freshwater tanks, but neither is limited to one tank type. Cyanobacteria will kill your plants. The bacteria will coat your plants and stop them from getting the light that they need to survive. It also sucks up the nutrients from the water column, substrate and further deprives the plants.

B) Best way to prevent cyanobacteria in your aquariums:
The best way to keep your tank free of cyanobacteria, is to keep up on your water conditions. Don't over feed, keep water quality at perfect or near perfect levels. The most important being the nitrate level, like plants, the cyanobacteria uses nitrates as food. Light is also important. Cyanobacteria, like plants use photosynthesis to survive. Phosphate levels also need to be in the right range. Make sure you have good filtration, good oxygen levels and good co2 levels.

C) How to tell if you have cyanobacteria:
1) the tank will have an odor to it and you will be able to smell it (very pungent odor).
2) the big indicator is if you have put your hands in the tank, (with or without gloves) then wash them thoroughly and can still smell the pungent odor on hands or gloves.
3) if you clean your decorations or plants and within a day or two the algae looking stuff comes back.
4) if the algae spreads very rapidly. Cyanobacteria colony's can double in size in 24 hrs.

D) If you have a cyanobacteria infestation what to expect:
Expect this stuff to be very resilient and do not die without a fight. Cyanobacteria will come back again and again if you don't figure out the main cause in your aquarium. Try and cure your tank one step at a time. Don't do multiple things at once. (that makes it hard to figure out the main cause in your tank). Do expect this process to take some time to resolve completely. Saltwater and freshwater aquaria are very fragile environments. Use caution and don't get in a hurry for results. Or you might find that your aquarium can't handle the changes.

E) How to rid your freshwater aquarium of cyanobacteria:
Start with water changes, they are the best way to rid your tank of cyanobacteria. Don't clean filters, they contain the good bacteria as well as the bad. If you do weekly water changes, you will lower the nitrate levels in your tank, which is good for your tank anyway. Also, make sure you clean the tank thoroughly including, decorations, fake plants and gravel. If you have real plants, try to clean them with a gravel vac or maybe even use a turkey baster, (try and suck the cyanobacteria off of them.) Do this every time you do water changes. The most common thoughts on this is to do a fifty percent water change then do a twenty five percent water change, then to do ten to twenty percent water change. Until your nitrate levels are at or near zero. You may need to do more than weekly water changes to get your tanks nitrate levels to zero. If the bacteria infestation still persists. Feed the fish less, they won't starve if you limit the feeding, just watch them carefully and make sure they are still healthy. Cyanobacteria does not seem to effect fish in the early stages, you might not even notice any problems at all. Continue to do your water changes. Also limit the light your tank gets. Cyanobacteria need light to survive, so by limiting the light your tank gets, you cut down the energy the cyanobacteria need to survive. Still do the water changes and keep the nitrates at or near zero. You might even put light on a timer to regulate the light more effectively. You can use the black out method to get rid of cyanobacteria, but this method is not the safest way to get rid of cyanobacteria. As the cyanobacteria dies, it lands on substrate and is absorbed by the water column. If not filtered and cleaned properly, it will cause your tank to foul even more when you quit the blackout. If you haven't filtered and cleaned enough, the cyanobacteria will return with a vengeance. Next, make sure your phosphate levels are within normal (which they should be if you are doing your water changes). Co2 and oxygen play a part in the life cycle of cyanobacteria. Make sure that you have good co2 levels and that there is plenty of oxygen in your tank. Add air stones if you don't have them and make sure you have good filtration. So what else can you do to rid tank? If you do water changes, limit light, don't over feed, make sure phosphates levels are good, the co2 and oxygen are good, and still the cyanobacteria thrives. You can use fish medication like Maredl Maracyn or your favorite type as long as it contains Erythromycin. Use as directed, don't overdose!! Medication also has draw backs. The bacteria can develop a resistance to the medication, so be careful when using. Also, medication may kill good bacteria. So you have to watch your tank very carefully. Test frequently to assure that your tank is healthy.

I found this information to late for my plants. I removed them from my tank and replaced them with fake plants. Cleaned all decorations and changed fifty percent of the water, then added the Erythromycin for five days doing water changes every other day. After two days the cyanobacteria started to fade away. After five days all signs were gone. I tested the water conditions at five days and found that the nitrates were high. I assume that the bacteria was masking the real nitrate levels to look lower than they actually were, did water changes till the nitrate levels were at normal levels. I also started to feed less food, and cut back the lighting two hours a day. It's been two weeks now and the tank looks great. The fish are healthy and active, and I feel much better that I may have found the cause for the problem. Time will tell.

I searched many websites and found many different opinions, on how to best rid aquariums of cyanobacteria. Not all websites had the same views on the process, or evan on the best way to start. The general idea was the same. I hope that this information may be of use to others. Sorry I have no pictures of my tank with cyanobacteria. I didn't want to use a picture from another site, without permission. You can find good pictures by searching images, in your web browser.

Example: {"Cyanobacteria" "Aquarium"} (cut and paste into image search in browser).

Some information was found at these websites, and some information was observed from my tank:

Introduction to the Cyanobacteria
Life History and Ecology of Cyanobacteria
Cyanobacteria - Wikipedia, the free encyclopedia
Nuisance Algae in Aquariums
TFH's The Planted Tank - "Cyanobacteria: The Ancient Pest"

"Of all the things I lost in life I miss my mind the most"

Work in progress what do you think so far:
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post #2 of 5 Old 10-17-2009, 12:26 PM
i had it for a while in my new set up.

in my case a 3 day total black out got rid of it.

i then upped the flow with the addition of a powerhead, made sure i was not letting my nitrate level drop and never saw it again.

apart from in the substrate along the front glass, used some black insulating tape to cover this area, job done
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post #3 of 5 Old 10-31-2009, 05:03 AM
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Just to clarify, this discussion is for FRESHWATER aquariums. There are many other factors invovled in discussing cynobacteria for a marine aquarium, and techniques for eliminating cyno will be different.
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post #4 of 5 Old 11-01-2009, 06:18 PM
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Very interesting read, keep it up. Found it useful.

1 Otos, 6 Guyana Leaf Fish, 2 Malayan Leaf Fish, 1 Orange Head Tapajos, 4 Bronze Cories, 3 Peppered Cories, 2 Panda Cories, 1 Skunk Cory

3 Thread-finned Acara, 1 Jurupari, 1 Spiny Eel, 1 Bristlenose Pleco, 1 Festivum, 1 Spotted Raphael

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post #5 of 5 Old 11-08-2009, 05:10 PM
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In the latest issue of Coral Magazine, a report on Cynobacteria is included. The update of importance is this... Cynobacteria are capable of taking in sulfer or nitrogen from the water when phosphates are not available.

Not good news for fishkeepers. Bottom line, increase water flow and do everything you can to encourage coraline growth.
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