Cyano :(

[gobytron]

Originally Posted by asylumdown

It's probably not a well accepted theory, but cyano bacteria has a disproportionately high demand for iron, and they've evolved family specific pathways to harvest it from the environment called siderophores that might be able to pick up the form of iron found in GFO. Research around shipwrecks and black reefs have recently shown a strong correlation between the grounding/sinking of iron based ships, and the rapid decline of surrounding reefs as simple algaes like cyano over-take corals. A recent paper linked it directly to the iron rusting out the hull.

There are also half cocked plans to dump enormous amounts of iron in the open ocean to encourage phytoplankton as a form of carbon sequestration. A great deal of the phytoplankton in the ocean is free living Cyanobacteria. Different genera than the kind on your sand bed, but the kinds we deal with have many of the same needs and capabilities.

Anyway it's clearly more complex, and there's more to cyano outbreaks than just iron, but I have anecdotally experienced drastic changes in its behavior just by starting or stopping the use of GFO. I use PO4x4 now, which isn't granulated, it's polymer encapsulated. Produces zero dust and theoretically releases less iron in to the water column. It's expensive as all get out, but I haven't had any issues with cyano since.

This is the kind of post that gets me off the classifieds.

Thanks for sharing this.

In my last 95 gallon, I had immense issues with HA, which I dealt with in many ways...once it was significantly reduced, I started running BRS GFO...

The BAM cyano like crazy...almost to the point that it was as bad as my HA was.

Even Chemi clean didn't work.

So at least to me, that theory holds some weight.

[martinmcnally]

I started using GFO after having non stop phosphate problems with a previous tank. I put it down to the old rock. It came from an older fish only tank with very poor lighting. It seems the phosphate was leaching out of the rock for years. Water changes would not reduce it. The only way I was ever able to get it under control was with the GFO. I am guessing if I reduced it now I would not have as much of a problem.

Are there other viable alternatives? I am building an algae scrubber at the moment actually. That might enable me to get rid of the GFO from what I hear from other peoples experience.

[gobytron]

asylumdown mentions PO4x4

[Myka]

Originally Posted by martinmcnally

Your right l should get a new bigger tank haha.

It's about 2 years old the rock is much older. If I increase the flow anymore it whips up the sand

Haha good plan!! I don't mean increase the flow, I mean adjust the rockwork so that the flow can get around the rock better. It looks like it has a lot of areas for it to settle. Your tank looks older than 2 years. I guess you're good at growing corals.

[Northvan]

We feel your pain. We've been fighting it for a year. We've done chemiclean (temporey improvement, but comes back), 3 days lights out with tank wrapped (no improvement at all), just finished a bottle of cyano clean with coral snow (1 month, $120, actually seems to have gotten worse).
We haven't yet tried erythromycin (antibacterial), not sure how to dose it.
Tank is almost no fun anymore.
Cyano sucketh .

[martinmcnally]

My cyano is completely gone now however it wasnt straightforward with the chemiclean.

I did the first clean as per the manual, basically everything off with an airstone running for 2 days. However after the 2 days I wasn't satisfied so I went another day. Removing the chemiclean seemed easy, 1 water change plus carbon and the skimmer was running again within a few hours.

However the cyano wasn't gone just reduced. I waited a week or 2 and did another 3 day treatment. This time was vastly different. The cyano was completely gone after 3 days. However removing it from the water was much more difficult. It took 3 water changes, new carbon and allowing the skimmer to overflow for around 10 days before it returned to normal and started skimming again.

Much harder on the second run than I thought but its gone and the chemiclean appeared to have no affect on coral or fish.