Convinced of a link between GFO and Cyano (and not the good kind)

[Myka]

I'm curious how you have come to the conclusion that the cyano in our tank is likely Oscillatoria? Is that your own ID from your microscope or are you reading this in your research?

Originally Posted by asylumdown

Take an organism adapted to surviving in an environment where some critical nutrient is limited and provide that nutrient in excess, you get steroid-like growth.

I see your point, and I understand your observations. I don't think your theory of steroid growth is always true though. I could think of a million examples, but the simplest one I can think of off the top of my head is sunlight for photosynthesis. Too much light can actually cause photoinhibition. So too much of a good thing isn't always better.

I think the ideas are interesting, but I also think there is more to it. I don't think it is as simple as adding iron via GFO. There are too many instances in my mind where cyanobacteria have popped up and it would be tough to blame it on iron. It makes me think about what the cause may be in those instances. Since cyanobacteria are such amazing critters I imagine there are many situations that could cause the growth. I'm also sure I've seen at least a dozen different species of cyanobacteria in saltwater systems.

I like this discussion though. It is discussions like these that get us thinking in new ways and solve old problems with new ideas.

[asylumdown]

Originally Posted by Myka

I'm curious how you have come to the conclusion that the cyano in our tank is likely Oscillatoria? Is that your own ID from your microscope or are you reading this in your research?

oops, missed that. What I get for typing on an iPhone all day. I was curious about it because there's so many species out there so I started looking in to cyano taxonomy. The Smithsonian Tropical Research Center maintains a great site with pictures of different cyano species in the wild, and Berkley also maintains a pretty good (if unsophisticated) site on cyanobacteria as well. The different genera are pretty distinctive in their behaviour, morphology, and appearance. Oscillatoria is the only genus that fits the bill as a group. It's the only one that forms mats of slimy 'cyano' like substrate coating goos in tropical marine environments. You can look at a bunch of pictures here: http://biogeodb.stri.si.edu/pacifica...lue/flocculent

Going beyond genus to species would take a microscope way better than mine, and even people who are experts on this as a career never seem to agree. This is what it looks like under my super crappy microscope (it's a video so you need to click on it):



That magnification wasn't high enough to see the heterotrophic and chemoautotrophic bacteria that live in association with the cyano mat, but you can see the super cool stretched out diamond shaped diatoms and a couple of the watermelon seed shaped dinoflagellates that live in association with the film. It's called "Oscillatoria" because the filaments re-orient themselves by oscillating back and forth until they are positioned as best as possible to receive the light, which is why the strands look like they're vibrating. I think it might be part of why cyano mats seem to shrink at night, the entire colony can deflate at night, then puff up over the course of the day as individual filaments stretch out to try and get the most light.

[asylumdown]

FWIW, based on those pictures, O. margaritifera, O. okenii, and O. subsalsa are great matches for the kinds we typically do battle with.

[Skim]

Well just thought I would put my 2 cents in. I had Cyno start to appear and this is what worked for me. Pull the GFO and GAC get some Seachem Purigen like 1L and pick up a few of the Seachem " The Bag" works perfect for the Media as it is fine. You can put it in the sump or better would be a small Canister or if you have an AquaClear hang it on the back or side. I did this and within the first day you could see the Cyno start to disappear and your water will sparkle. This stuff lasts quite a while and can be regenerated. It rapidly removes Organics from the water.
One other thing maybe I missed it but is your skimmer working as it should?
The other thing maybe lights old tubes or bulbs if you are use them.
Give the Purigen a try, its simple safe.
The other thing I just thought of that seem to help also was Brightwell Aquatics-Microbacter 7, with a large tank you may need to get the 2L bottle.

Good luck.
All the best.

Mike
P.S one other thing you can try if you use the Purigen is cut back the lighting time or shut them off for 2 to 3 days. That should get ride of the stuff real fast.