If you plan on keeping a saltwater aquarium for any amount of time, whether it is a reef tank or a fish-only with live rock tank (FOWLR), you are likely to experience an outbreak of cyanobacteria and diatoms.  Cyanobacteria or “Cyano” is also referred to as green slime algae (also comes in red and brown).  As it’s name implies, Cyanobacteria covers rocks and sand with a thin slimy film.  And while it is easily removed by siphoning, if the conditions that support it are not improved, then it will quickly return, unless you follow these steps.

Cyanobacteria and diatoms are brought on by the following factors:

• - high phosphate (>.5) and silicate
• - high nitrates (>25ppm)
• - insufficient current/water movement
• - high organics
• - low alkalinity (<3.0 meq/liter or <150ppm)
• - low pH (<8.2)
• - not enough grazers/inverts/sand stirrers (hermits, turbo snails, nassarius snails, seacucumbers)
• - not sufficient coverage of rock with corals (corals and algae do compete, so tip the scales in your favor by stocking to cover 60% of your rock with corals).

Three products that work to treat the symptom (not the cause – see above) are as follows:

Chemiclean

, which will eradicate the cyanobacteria (reef safe – we’ve used it in our service business for years)

Granular Ferric Oxide (removes phosphate and silicates) – we prefer Rowaphos, but there are other brands that work as well too.  This is great for removing phosphate, although a bit expensive.  Remember to focus on lessening the source of input of phosphate into your system (i.e. tapwater and foods).  For tapwater we filter with RODI (target is zero TDS).  As for the foods, we strongly recomment rinsing your frozen foods prior to feeding.  You’d be amazed at the amount of gook (scientific term) that would otherwise go into your tank/system.

• Doxicyclene hyclate – it has been years since I’ve used this for treating RTN (rapid tissue necrosis) in corals, but we also noticed that it was great for temporarily eradicating cyanobacteria.  I say temporary, because this is just treating the symptom and not the cause.  As long as the original cause (see above) is still there, the cyano will likely return.

If your type of saltwater tank is a fish-only with live rock (FOWLR), you are always going to have significantly higher phosphates, nitrates, silicates and organics to deal with than you would in a reef tank – even if you had the same number of fish in a reef tank.  This is because in FOWLR tanks, there are no (or very few) corals, sponges, coraline algae, clams, filter feeders, etc. to help remove nutrients from the water.

So with a FOWLR tank, you will need to be more aggressive with use of carbon, GFO (granular ferric oxide – removes phosphate) and with the removal of detritus.  I strongly recommend “storming the tank” at least twice a month (during normal/ideal conditions), but I would recommend doing it once a month in your current situation.

What I mean by “Storming the tank”, is putting a submersible powerhead pump on a stick/pipe and blast the rock to liberate detritus that has collected in the live rock.  And then having some type of mechanical filtration in use to remove the detritus now that it is suspended in the water column.

To do this you can use a canister filter, D.E. filter (diatomacious earth), or even a small powerfilter (hang-on-the-side).  Or if you don’t have any of these items, you can storm the tank with the powerhead and then siphon it off the surfact of the rock/sand as you do a large water change.  With this method I recommend blasting with the powerhead twice during the water change, allowing it to settle out for siphoning between blasting.

So if you end up with an outbreak of cyanobacteria or diatoms in your reef tank or fish-only tank (FOWLR), consider yourself fortunate that it is just cyanobacteria and diatoms, which are relatively easy to get rid of, and not something more difficult like bryopsis or hair algae.  And remember, you are better off preventing than reacting.

Technorati Tags: chemiclean, cyano, cyanobacteria, diatoms, fish-only tank, FOWLR, green slime algae, phosphate, red slime algae, reef tank, rowaphos, slime algae

There are all kinds of algae problems an aquarist can experience in keeping saltwater aquariums, particularly with reef tanks. But none of them can be as nightmarish as Bryopsis.

Unlike most other algae, such as hair algae or cyanobacteria, Bryopsis does not respond to most removal methods. Even a normal algae problem can be extremely frustrating or even lead to someone giving up and shutting down their tank. But that doesn’t have to happen. There is a solution and I’m going to share it with you here in just a moment.

Typically, most algae problems such as hair algae or cyanobacteria, can be solved with a combination of:
- elevated pH
- increased water circulation
- removal of phosphates and nitrates
- removal of detritus, and
- addition of algae grazers (tangs, hermit crabs, snails, emerald crabs, urchins, sea hares, etc.)
- manual removal by humans (i.e. plucking, scrubbing, siphoning, etc.)

But Bryopsis is different, as it does not respond to these methods. Actually, it can often grow even more because of such methods (especially manual removal, which can feed asexual reproduction via fragmentation). And even biological controls such as adding grazing invertebrates and tangs is not only not very effective with Bryopsis, but it can be expensive (them critters ain’t cheap).

I wish I could say it was my idea – far from it. In fact, I have been dealing with a bout of Bryopsis recently in our 950-gallon saltwater reef exhibit at the Ocean Explorium, where I am Curator. And I was researching solutions to my problem when I cam across this solution. Here’s the link.

http://reefcentral.com/forums/showthread.php?s=&threadid=1113109&perpage=25&pagenumber=1

It explains the whole process in fair detail, with photos of results, showing the Bryopsis dying off and disappearing as a result of the treatment. I’ve also done more research on this method (thank you google) and it has actually been widely used with consistent successful results. And yet, it is a mostly unknown method.

Most people who get cursed with a Bryopsis algae outbreak, work like crazy for long periods of time, getting very frustrated, and still not even make a dent in the problem. Bryopsis algae outbreaks are usually caused by a new addition, where the algae comes in as a hitch hiker on a new coral or piece of live rock, or even a snail shell. So I’m glad I found it and even more glad to share it with you. Please be sure and share it with your friends too.

The method uses increased Magnesium levels for three months (1600ppm compared to the normal 1300ppm), to bring the Bryopsis to its threshold for binding Magnesium. This causes the Magnesium to then perform as an enzyme inhibitor, making the Bryopsis shut down and die off. Once this happens, the grazers in your saltwater aquarium will clean up the remains.

Point of caution: Be sure not to raise the Magnesium level by more than 100ppm per day.

Please post a comment here on the blog to share your feedback, or to tell your story if you are having any problems or frustrations with your saltwater aquarium. We would love to help you out in any way we can.

Technorati Tags: algae, algae removal, bryopsis, bryopsis algae, cyanobacteria, hair algae, magnesium, problem solving, reef tank, saltwater aquarium