Nat's Wondrous Aquarium Blog

Reef Tank: Cyanobacteria Defeated

Tuesday, January 26, 2010

After a battle spanning most of 2009, I am happy to report that the cyanobacteria plaguing my reef aquarium has finally been beat. I've been holding off on this post for most of the month of January, waiting to see if a relapse might occur. As it hasn't, I'm ready to summarize a struggle that occupied most of 2009 and how I finally won the war.

The biggest problem with a major algae outbreak in the aquarium is how demoralizing it can be for the aquarist. In the end, all the money and hard work we invest in this hobby is for the purpose of having a beautiful aquarium in the home. A tank overgrown with red slime is an eyesore, and after months of ineffective manual removal thoughts being to turn towards tearing the entire setup down, starting over, or getting out of the hobby altogether. The most important thing is to stay diligent, even if the process extends for months.

In this post I'll outline my thoughts around how the cyanobacteria formed in my tank, what methods failed to remove it, and how I finally succeeded.

What Caused the Outbreak
The cyanobacteria began settling in around June of last year. I attribute this to a combination of overfeeding and the loss of a fish that I was never able to remove, leading to a spike in nutrients from decomposition. Additionally, I was having some serious detritus issues, lacking a proper way for exporting the organic matter accumulating within my tank.

Another mistake I made was not removing the cyanobacteria immediately once it began forming on the substrate. I was not aware of how tenacious it can be once it begins growing within an aquarium. Manually removing as much as possible as soon as it becomes visible within the tank should be the number one priority of a reef keeper.

What Didn't Work
Most of my posts on this blog over the last half of 2009 involved various attempts at defeating cyanobacteria:

Rising Nitrates
In April I started to note my nitrates rising. I replaced my RO filters, which needed to be done anyway, but testing revealed this wasn't the source of the nitrate issue. In hindsight it was more likely detritus build up and overfeeding leading to the rise in nitrates.

Zeolites, Purigen and AlgaeFix
In June I tried reintroducing zeolites, to little effect on nitrates. I added Seachem's Purigen chemical filter media, which I believe helped stop the rise of nitrates, and temporarily reduced them. And finally, I tried API's AlgaeFix Marine, a chemical additive that was quite popular on the reef forums and supposedly could magic away any algae outbreak.

AlgaeFix did absolutely nothing against the cyanobacteria, and had only moderate success on the green hair algae. In addition, I noticed a die off in snails and some shrimp after two weeks of the recommended dose. I would not encourage use of this product, regardless of the positive things one might read on aquarium forums.

Bolstered Clean Up Crew
In July I brought in a larger clean up crew to deal with the detritus buildup and hopefully stir up the sand bed preventing cyano from forming. A large number of these snails died off immediately, something I am inclined to link to the AlgaeFix additive.

Manual Removal
By July I'd been reduced to manual removal, a process I performed at least twice a week for the rest of the year. Manual removal involved getting into the aquarium with my hands and a toothbrush, scrubbing the cyano off the rocks so it wouldn't overgrow corals, and removing large mats of the stuff from the substrate. Due to the decaying organic matter and constant water changes for removal purposes, parameters in my small tank were exceedingly hard to keep stable, and a number of corals were lost as a result.

Algae Filter and Vodka
In October I converted my filter into an algae scrubber with Chaetomorpha macro algae. I think this provided a marginal amount of nutrient export, and definately boosted the population of copepods and other beneficial bugs in the tank. But what ended up being the miracle cure was the addition of vodka dosing.

How I beat Cyanobacteria
I absolutely attribute the daily dosing of a small amount of vodka into my reef aquarium to the end of the cyanobacteria problem. Rather than butchering the explanation of how an organic carbon source like vodka effects an aquarium, I will link to an Advanced Aquarist article that will do a much better job:

http://www.advancedaquarist.com/2008/8/aafeature3/

For my dosing, I followed the regimen documented by Melev on his (infinitely useful) website. This schedule began with what was merely a drop of vodka per day, and built up to a full dose of nearly 1ml daily. By October 23rd I observed that nitrates, which had been close to 40ppm for the majority of 2009, had been reduced to zero. They have tested at 0 ever since.

I had long assumed that the nitrates were the primary source of fuel for the growth of the cyanobacteria. Confirming this, after the nitrates were testing at 0 I noticed the health of the cyano immediately decline. Once a very thick carpet of deep red coloration, it began to take on more of a browned out appearance, growing much thinner. Eventually it changed form, appearing as strands waving in the current rather than a thick mat covering the substrate. Manual removal went from a daily process to weekly, and eventually became completely unnecessary. By mid-December my tank was free of cyanobacteria.

Another good article on vodka dosing: http://reefkeeping.com/issues/2008-08/nftt/index.php

Dosing vodka as a carbon source has cured my tank of nitrate issues, cyanobacteria and hair algae, and (indirectly) detritus build up. The corals, invertebrates and fish have never looked healthier, and I've been able to resume heavier feeding without issue. I would suggest researching this method for anyone dealing with nutrient and algae issues in a marine aquarium.

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Reef Tank: Zeovit Notes

Monday, June 23, 2008

After a month of running zeovit filtration and supplements in my tank, I can finally remove myself from their exceptional marketing photos and take a look at what benefit it had provided for my tank. Given that my system and corals are still very young, its hard to draw any conclusive evidence. Further complicating the matter is that my tank has been quite healthy and algae-free since inception, and maintains a very low bioload (still only one fish). That said, I've noticed some nice coloration from all SPS species, especially my birdsnest which has taken a very bright pink coloration. Good polyp extension all around.



One thing the good people selling zeovit systems will impress upon you is that a special reactor is useful for running the filtration media. Giving the rocks a shake every day loosens the mulm that collects within the media, letting it drift into the system and feed the corals. I've found that for smaller tanks, running this media within a simple hang on filter, the Hagen Aquaclear, works just as well. This filter has a nice media basket with convenient handles at the top above the water surface. You can easily remove the top and give these a good shake to release a great cloud of organic filth for your corals to feast upon.

I've found the Aquaclear to be a great all-purpose filter. Currently I have a bag of activated carbon and a bag of liverock rubble running, with the rest of the space filled with approximately 1/3 liter of zeovit medium.

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Reef Tank: More Testing

Wednesday, March 5, 2008

Here is a graph I generated showing the process of the nitrogen cycle in my tank to date. Note that the x axis is not to any particular scale as I don't test at regular intervals. Still, it shows all tests going in the right direction, towards 0.



Today I got another set of tests for the reef aquarium. Once corals have been added to the tank, it is important to keep levels of calcium high in the water so that they can create their skeletons. It is also important to keep the carbonate hardness of the water level (also known as alkalinity) high to make this calcium accessible to the corals and buffer against pH swings. The third test measures phosphates, which form from animal waste and precipitate calcium, making it unavailable to be used. Phosphates can also serve as fertilizer for algae growth. To summarize, I am looking for calcium levels between 400 and 500ppm, KH at 140 to 215ppm, and no signs of phosphate.

Todays Parameters:
Temperature: 81F
Specific Gravity: 1.026
pH: 8.0
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 20ppm
Phosphate: 0ppm
Calcium: 480ppm
KH: 179ppm

I must say I'm surprised at how well everything has gone so far. The water levels above, aside from a slightly low pH, could probably sustain coral growth quite well. With ammonia and nitrite undetectable, the tank is ready to be populated. I am going to hold off at least another week before stocking, while I finalize the list of corals and fish I want to keep in my tank. I also need to upgrade my lighting fixture to metal halide before I can order any coral. Another week or two with the snails and hermits should help the tank to slowly prepare itself for these additions.

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Chemistry: The Nitrogen Cycle

Wednesday, February 27, 2008

As mentioned previously, my reef tank is currently going through a startup phase in which the nitrogen cycle becomes established. As there isn't much for me to do until this phase completes itself, I decided to dig a little deeper on the chemistry of this cycle and how it specifically relates to reef aquaria.

Fortunately for those of us who spent too much time goofing around in high school chemistry, there are a number of talented professionals contributing to the knowledge base. Of particular note is Randy Holmes-Farley, a chemist at Genzyme (which just so happens to be down the street from where I work). He writes articles for several online reef aquaria journals, and this morning I enjoyed reading two on the nitrogen cycle: Nitrite and the Reef Aquarium and Nitrate in the Reef Aquarium.

Of specific interest in these articles were a few points that differ in marine aquaria from freshwater systems, and that also defy what is passed along in forums as conventional wisdom. For one thing, it appears that in saltwater systems nitrites are not considered highly toxic unlike in freshwater tanks where they are considered as deadly as ammonia. Randy also lists out proven methods of eliminating nitrates in the reef tank, which though also not considered highly toxic, can be contributors to nuisance algae. Both articles are a great read for those looking to get an introduction to these steps in the nitrogen cycle.

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