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
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
Time to change the RO/DI filters, apparently
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