I've often scraped cyano over the years in the tanks....I would siphon, scrape, and net out the big pieces.

I wonder if the sponges may have contributed to the problem. I agree the bacteria may have killed off some beneficial bacteria....I don't really know, because I use a skimmer and have never seen anything like this. :confused:

im sorry bev

if you need someplace to move the survivers to i have the room until the tank settles

only thing i can think of is toxins in the cyano...or as mipmap said it was handling a good bit of your bioload. Scraping it removed part of the biofilter and all the loose ends in the filters started releasing ammonia

surprised it happened that fast

Sorry about the loss bev, that CB was awesome!

I wouldn't put a whole lot of stock in the scraping of the cyano as being the cause. Cyano (at least in freshwater) has the ability to fix nitrogen from more than just water borne NH3/4/NO2/NO3. One of the major reasons why planted tanks can have major outbreaks in very nitrogen depleted/limited systems.

I personally would be looking to alternate sources where a toxin may have been introduced - maybe the scraper came in contact with a chemical... New air freshener maybe? There are a million ways a toxin can be introduced into a tank, figuring out how it happened is always a challenge.

Andy

I'm so very sorry for your losses Beverly. Hang in there and best wishes for a speedy recovery of your tank and good luck to the survivors.

I have no idea what the black stuff could be.

Good luck.

what really gets me is how quickly everything went down. I did some searching myself and didn't really find much. Sorry Bev :cry:

Thanks, everyone, for your kind comments :smile:

After a very sleepless night, I found the tank to be in slightly better condition this morning. The two remaining fish are alive and swimming about, though not as they had been with their other two fish friends :sad:

Shrooms are enlarging a bit, which I take as a good sign. My favourite macroalgae isn't doing very well, sort of seems limp. Other macroalgae seems fine, but who can really tell since it's a coarse brown variety.

After lots of thought, I'm guessing the black stuff in the foams was dead cyano, which may have accounted for the rise in ammonia.

I may have unleashed a sort of red tide by dislodging the cyano from the tank wall and into the water column, but this is only speculation. Still have this cyano on the bottom of the tank in some places, as well as on some of the rock. The 120g has about 150 lbs of LR.

Only began to notice the cyano growth after using a UV sterilizer to get rid of what we thought was ich on the chevron butterfly. Turns out the fish had a viral infection that was cured by increased tank temps from 77F to 82F for about 3 weeks. Maybe the cyano growth was fueled more by the temp increase than the UV, though cyano growth was at its greatest where the water came out of the UV hose.

A few snails were found on their backs this morning. Put them at the front of the tank and turned them over to watch if they move away or if they are dead.

Still feel really freaking bad about the whole incident, which may not be over for several days as livestock begins to either flourish again or die slowly :cry: :cry: :cry:

Dang :cry: This is not the first major disaster in my reefing career, but that doesn't make this one any easier to handle than the others :sad:

As the morning progresses, the button polyps are opening, so are the brown and green star polyps. Mushrooms are doing better. Fish are out and swimming around quite well, but their feeding response is a little slow, mostly I think because they are missing the heavy feeders that perished. Looks like the bad stuff in the tank has passed, though :smile: It'll probably take me a few days to get over the shock of the whole episode :cry:

One point of interest is that both dead fish were found with all their fins wide open as if they were in full display. Other fish that have died for various reasons all had their fins clamped closed.

Although I can't say what happened, I will say that it is very unlikely that Cyano was the immediate cause. I have dislodged tons of the stuff over the years with no bad effects.

As a side note though. When I lived in Vancouver in the late seventies, we used to light our tanks with Grolux tubes. We had lots of Cyano, but under that lighting it was black. :eek:

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Beverly, sorry about your luck. I've been thinking about your first post when you said, I think you are correct that the black matter was dead cyano, and that cyano had taken over the bio loading in your tank. I'm glad that your tank is recovering now. I believe that we can all learn from this experience; to not let cyano fester in our tanks.

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boB,

There are many species of cyano. The cyano in the 120g was not the usual kind that I have had over the years, which was fluffy, easily blown off by turkey basting, and showed signs of photosynthesis by producing bubbles by mid-afternoon. The stuff in my 120g did not blow off at all when basted and required a reef-safe scouring pad to remove it. Also, there were no signs of photosynthesis in the form of bubbles on this cyano. Maybe I got lucky :evil: and got a species of cyano that emitted toxins when disturbed. That's the only thing I can think of at this point, especially after testing the water from our RO/DI unit this morning and finding .5 ppm ammonia in it :eek: Time to change the RO/DI filters, apparently :neutral:

Danny,

When I look back on yesterday and on the months we had very few snails in the 120g, most of the growth on the back of the tank was green and fluffy like regular old nuisance algae. There were places in the green stuff where the odd snail would venture up to eat it and leave bare spots, so it couldn't have been cyano in those places.

However, since the temp increase three weeks ago, the green stuff began to turn red and where there was no green stuff, the tough cyano began to grow there too. I presume, perhaps incorrectly, that the cyano grew on top of the green algae and that's why it all looked like cyano, though there was green algae beneath it. Underneath both green algae and red cyano, there is a healthy growth of coralline, likely due to the indirect light coming in from the window behind the tank.

I highly doubt the cyano "took over" the bio-load, though. I have three different species of macroalgae (brown, red, and green) in the tank and all are growing like crazy. The brown macro is in four fist-sized clumps, two fist-sized clumps of green macro, and only a bit of red macro in one place. Just last week I removed over half each of the two clumps of green macro that were threatening to over grow their areas.

I dunno. I'm stumped at this point. Still have this cyano on some rock and it won't blow off :evil: :eek: