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.

Labels: Algae, Chemistry, Maintenance, Parameters, Reef Aquarium

As a follow up to a post in April, I recently converted the Aquaclear filter into an algae tumbler. Stocked with a small amount of live rock rubble and a large ball of Chaetomorpha algae, lit by a 15 watt compact fluorescent light. After adding this Algae on Thursday, testing for nitrates has indicated that the algae is effective: test results dropped to <5ppm from 20ppm last weekend.



If this continues to be successful, I'm going to look into a smaller LED light source for a more streamlined look. The current fixture splashes some of the warmer yellow colored light into the tank.

Another issue I've been dealing with is dropping pH, which has dropped below 8 at least twice in the past month. I've responded by adding Seachem Reef Buffer every other day, and increasing my testing. I've been considering adding a pH probe to my controller to make monitoring easier.

Labels: Algae, Equipment, Parameters

Tonight I tested some algae-specific parameters for the first time since changing my filtration strategy. The good news: nitrates dropped from 40ppm to 0. Phosphate remains at zero as always. Looks like the Seachem Purigen was a success.

The bad news is that I still have algae. After two weeks of doing the API Algaefix, I noticed it was growing back slower after a cleaning, and that some of the stringy algae was less green. Supposedly this is a sign of it working. I plan on continuing dosage for now. I'm hoping that by removing the nitrate, my corals will bounce back soon, and the algae will begin to disappear.

Another item of note, my clownfish have begun to display mating behavior. They've also been regularly digging a small pit in the gravel, which seems odd as I was under the impression that they generally prefer flat, solid surfaces for egg laying.

And finally, after a year of barely keeping SPS alive, I've been considering switching over to primarily soft corals. Live Aquaria has recently stocked up on some very interesting and colorful species, flying in the face of conventional wisdom that all soft corals are brown.

Labels: Algae, Maintenance, Parameters, Reef Aquarium

In light of my continued issues with nitrates (~40ppm) and the resulting algae, I've decided to make a few changes to the filtration mediums used in the filter. Up until now I've been running two bags of carbon along with some live rock rubble. Carbon is great for polishing the water, but it isn't actively helping with an accumulation of organics. The live rock has proven a good breeding ground for micro fauna (I regularly find abundant copepods and sponges), but there isn't enough volume to consider it an effective biological filter.



First, I reintroduced the zeolite media I had experimented with last summer. The highly porous nature of zeolite absorbs impurities and serves as a breeding ground for beneficial bacteria that reduce organics. I started low with the volume of zeolite, and hope to increase it based on how the corals react.



Secondly, I added 100ml of Seachem Purigen. This is a porous chemical filtration medium that works as a sponge for organic matter in the water. By removing this material from the water column, it never has a chance to complete the nitrogen cycle and become nitrate. Thanks to the abundant volume of the Aquaclear filter, I am also able to continue running a bag of carbon and the live rock rubble.



The last change to my maintenance routine is a little more controversial, at least in my mind. I am generally very conservative about introducing any form of additives, and especially opposed to chemical treatment of algae. That said, after reading a long thread about the effectiveness of API's Algaefix, I had to try it. The experiences of many aquarists confirmed the claim that this product will not harm anything within the tank, from fish to invertebrates, but will eliminate most forms of algae within weeks. An $8 bottled solution is very tempting after spending a few months scraping algae and performing multiple water changes each week. 

Labels: Algae, Maintenance, Parameters, Reef Aquarium

Here I am prattling on about my nitrates rising, completely oblivious to the aging to do item "Buy RO filters for aquarium". Thankfully Ocean@Home posted a reminder that parameter issues often start at the source, the water you put into your tank. Doing frequent water changes to combat nitrates isn't going to help if the tap water is the source of your nitrates. Tonight I'll test my tap and RO output just to verify.



A quick online order from Drs. Foster Smith, and I should have some new RO filters here within the week. I took the opportunity to order a new XM 15k metal halide bulb as well, another yearly maintenance task I've been slacking on. Better late than never!

Labels: Link, Maintenance, Parameters

Over the preceding two months I've noticed the nitrate levels in my reef tank creeping up from unmeasurable to 20ppm. I blame this squarely on a Glassbox post about fish being fed enough; worried that I was compelling my fish to be "coralexic", my tank has since become an all you can eat Chinese buffet. I believe the elevated nitrate level is responsible for some of my corals browning out. Also I've noticed a few strands of dreaded hair algae appearing within the tank, as well as increased diatoms on the glass of the tank.

My plan is to keep up with my weekly 5% water changes, and also to introduce a new form of nutrient export. If anyone has advice on the choices below, please volunteer your expertise in the comments. Also if you'd like to sign up to come over and do some of the water changes, please feel free.

Option 1: Convert Aquaclear filter into an algae scrubber



Originally I bought this filter with intent of modifying it into a refugium, filled with live rock rubble and chaeto. Since, I've been running a small amount of rubble and two bags of carbon. This option would involve adding a small light above the filter, installing a grate over the exit, and filling the filter with chaeto algae to remove nitrates.

Pros: cheap, fun project with existing equipment
Cons: reduced volume of carbon, not enough volume for a useful quantity of algae

Option 2: Hang-on refugium



Although a real sump is out of the question for this tank, there are out of the box options for hang on refugiums. This would perform roughly the same function as a modified Aquaclear filter, but with a lot more volume. These things always struck me as somewhat gimmicky though. I would run mostly chaeto within the refuge, along with some sort of sand bed and live rock rubble.

Pros: More volume, greater biodiversity, out of the box solution
Cons: Expensive, unsure of their effectiveness, possibility of flooding?

Option 3: Another solution?
Larger skimmer to cut the problem off at the source? Less feeding? Better sand bed maintenance? Some sort of addition clean up crew? All of the above? Let me know what you think.

Labels: Algae, Equipment, Parameters, Reef Aquarium

Over the past few years I've learned about one of the secret joys of adulthood: the self-given Christmas present. This year I picked up a Canon G10 to replace my aging and broken Powershot (early results of learning its manual controls shown above). I also decided to get something I'd been looking at for awhile, the Reef Keeper 2 controller from Digital Aquatics.



Of course, as soon as I ordered it Reef Builders put up a post about the new Reefkeeper Lite controller coming out sometime this spring. I've been working with computers long enough to know that what meets your needs now is always more important than what might be coming out in the near future, but still funny.

The one problem I'm looking to solve with this controller is my fluctuating temperature. Living in an apartment without a thermostat can be frustrating with a reef aquarium. One would generally not expect to have problems with water going over 80F in New England during the winter, but radiators and smaller rooms can put you in a tough spot. With this controller, I will be able to activate a fan to begin cooling when water temps exceed 80F, and turn off the metal halide lighting if it goes over 83F. Hopefully it will also maintain more precise control over the heater as well.

I'm not exactly sure what other features will be of immediate use to me. The ability to quickly turn off filtration devices for feeding will be nice. I'll have to explore the possibilities when it arrives.

Labels: Equipment, Parameters, Reef Aquarium

This morning I placed an order at Live Aquaria for a stony coral frag pack. While stony corals can be more difficult to keep because of their increased need for light, calcium, and water current, I find them some of the more interesting species and was what I always envisioned keeping in my tank. The package I ordered is for five frags (small fragments from a larger colony) of aquacultured coral colonies. Aquacultured specimens, as opposed to wild card, are purportedly more tolerant of aquarium conditions and less likely to be severely traumatized by the introduction to a new tank.

My new metal halide fixture arrives tonight as well, so I hope to be able to get that setup and post pictures of the tank. This should represent the last piece of equipment that was part of my original tank plan, although I've already thought of several things I'd like to change and upgrade in light of the decision to keep stony corals primarily.

Parameters from Last Night:
Temp: 80F
SG: 1.025
pH: 8.3
Ammonia: 0
Nitrite: 0
Nitrate: 20ppm
dKH: 9
Calcium: 400ppm
Phosphate: 0

Labels: Coral, Invertebrates, Parameters, Reef Aquarium

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.

Labels: Chemistry, Parameters, Reef Aquarium

On Saturday morning I did another round of tests and found ammonia to have dropped to zero. Nitrites were still low and nitrates were elevated to 40ppm. I decided to try and add some of the first inhabitants to my aquarium, a group of snails and hermit crabs who could feast on the new growth of diatoms and the stuff that came in on the live rock.

I went to Skipton's Pet Center in Boston, which is the best fish store in metro Boston, as far as I know. They helped me settle on a dozen Nerite snails and ten hermit crabs, a few different varieties of Clibanarius, including red and blue colorations. Both snails and hermits originate in the Caribbean and are quite common, which makes them affordable to purchase compared to other species. The snails are intertidal and therefore spend a lot of time crawling above the waterline to breathe. Everyone appears to have survived their first night, and I've been watching both snails and crabs tear into the diatoms on the rock and glass.

Still trying to figure out the white balance while shooting under actinic light, so please excuse the yellow tone of these photos. The picture of the blue hermit crab is closer to the correct coloration. Also, if you go to a larger view of the snail photo, you can see the barnacles on its shell extending their feeders. Pretty cool!







Saturday Parameters:
Temperature: 81F
Specific Gravity: 1.026
pH: 7.9
Ammonia: 0ppm
Nitrite: 3ppm
Nitrate: 40ppm

Labels: Invertebrates, Parameters, Reef Aquarium

Photo Credit: Prof. Gordon T. Taylor, Stony Brook University, USA

Last night I noticed a golden-brown colored dust growing on the substrate and rocks. I spent some time searching for algae species identification charts, and eventually came across an About.com article regarding diatoms. A trip to Wikipedia and some other resources confirmed that was what I had most likely observed in my tank. Of particular interest to me was this section from About:

This type of algae outbreak typically occurs when a tank is just completing or has finished the nitrogen cycling process, new live rock is introduced, as the curing process can add nutrients when some organisms on the rock dies off, or tank maintenance has been neglected.

Obviously that would pertain to current events in my reef tank. I had assumed that ammonia levels, which had been as high as 8ppm three days earlier, would require at least another week to subside, and had resolved not to waste my time and test kits checking it every day. The growth of diatoms and subsequent information about them forced a change of mind, and I conducted my usual tests this evening with surprising results: ammonia had indeed dropped to somewhere between 0.25 and 0ppm, an impressive down swing from the levels recorded on Sunday. Nitrite and Nitrate were still high, but that would be expected as they are the products of processed ammonia.

Also of interest was this summary of diatoms and their use of silicates, found in the Wikipedia article:

Diatoms cells are contained within a unique silicate (silicic acid) cell wall comprised of two separate valves (or shells). The biogenic silica that the cell wall is composed of is synthesised intracellularly by the polymerisation of silicic acid monomers. This material is then extruded to the cell exterior and added to the wall. Diatom cell walls are also called frustules or tests, and their two valves typically overlap one other like the two halves of a petri dish. In most species, when a diatom divides to produce two daughter cells, each cell keeps one of the two valves and grows a smaller valve within it. As a result, after each division cycle the average size of diatom cells in the population gets smaller. Once such cells reach a certain minimum size, rather than simply divide vegetatively, they reverse this decline by forming an auxospore. This expands in size to give rise to a much larger cell, which then returns to size-diminishing divisions. Auxospore production is almost always linked to meiosis and sexual reproduction.

Once again, an insightful article from Randy Holmes-Farley helps to clarify both the cause and effect. As mentioned above, diatoms construct their cell wall from silicate, hence their presence could be considered an indicator of silicates being present in the aquarium. His article discusses how silica occurs in the ocean and in the aquarium, as well as what organisms use it and how it can be controlled and dosed. Great stuff.

My assumption is that there would be a high level of silicates found in my tank due to a number of recent inputs:
• Unfiltered tap water for the initial tank fill
• Sand and sediment on the live rock
• Live sand substrate

So there should be plenty of raw material for diatoms, in addition to the high levels of light for photosynthesis (I've been running the tank lights 8 hours a day) and nitrate for fertilizer. Conventional wisdom seems to indicate that after the initial outbreak of diatoms in a new aquarium one can expect green algae to replace it. My initial hobbyist panic response to seeing my pristine new white sand bed polluted with some form of new algae has since been replaced with curiosity now that I've learned about the circumstances under which it appears. I intend to see if I can get a sample out of the tank and take a look under the microscope this evening, as the imagery on Wikipedia is quite stunning.

Todays Parameters:
Temperature: 81F
Specific Gravity: 1.026
pH: 7.9
Ammonia: .025ppm*
Nitrite: 5ppm
Nitrate: 10ppm

* The color of the ammonia test was actually somewhere between 0.25ppm and 0ppm, and closer to 0. In the interest of caution I am rounding up on the chart.

Links from this post:
Randy's article in Advanced Aquarist about silica and diatoms:
http://www.advancedaquarist.com/issues/jan2003/feature.htm

Wikipedia article on diatoms:
http://en.wikipedia.org/wiki/Diatoms

About.com article on diatoms:
http://saltaquarium.about.com/cs/algaecontrol/a/aa091100.htm

Labels: Algae, Parameters, Reef Aquarium

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.

Labels: Chemistry, Parameters, Reef Aquarium

Once live rock has been introduced into a new aquarium the waiting game begins. Live rock brings with it life of all forms, from simple bacteria and algae cells up to more advanced life forms like sponges, worms and even coral polyps. Naturally on the long journey from the South Pacific (specifically, Tonga) much of this life perished. The combination of live and dead organisms helps to jump start the nitrogen cycle. Reef Central has a good FAQ regarding the nitrogen cycle as it pertains to reef aquariums.

In short, dead organisms arriving on the live rock decay, creating ammonia which is toxic to all life and probably killing off other organisms that had managed to survive the trip. Fortunately bacteria present in the rock are capable of converting ammonia to nitrite (still toxic to marine life) and then converting it further to nitrate (somewhat toxic at higher levels, but not as bad as the other two). As the patient new aquarist, I must sit back and watch this cycle slowly take place over the next two to six weeks, watching via test kits as the levels of ammonia, nitrite and nitrate change in the aquarium. Once the bacteria has taken hold ammonia and nitrite levels should read at 0 ppm. Nitrate may still show up in minute levels and can be minimized via water changes.

I plan on testing the parameters every four days or so to monitor this cycle, and to perform 20% water changes once a week to further reduce toxins. As a sign of a successful cycle beginning, we're looking for a drop in ammonia and a rise in nitrate to indicate the bacteria are at work. The protein skimmer has been pulling out some very light skinmate but doesn't appear to be quite as dialed in as I would like. I'm not sure if this is related to a lack of nutrients in the water to be skimmed or some other variable.

Todays Parameters:
Specific Gravity: 1.0255
pH: 7.9
Ammonia: 8ppm
Nitrite: 5ppm
Nitrate: 10ppm

Labels: Parameters, Reef Aquarium