Cyano? Help please.
 

So this is my first real issue with any kind of algae, and the tank has been running well over a year so I guess I have been lucky, but this stuff sucks!

I have had conflicting reports from others - Some believe it is cyano, some say diatoms. It's slimy, stringy, and it generally disappears at night... Like totally gone at night. In the morning it's in full bloom. I tried removing it + doing a black out for three days... It came back every day regardless of no light (tank is in the basement - so no residual light). Now it's worse than ever.. Coating mostly my sandbed. The bottom of some rocks are affected but it's mostly the sand.
http://img.photobucket.com/albums/v7...ps24aa0694.jpg

Looks like cyano to me. Lots of threads this year on dealing with it, hit the search feature and see what others have done.

I'm currently dealing with the same slimy nightmare. A large part of the problem for me personally is that I didn't keep the sand clean. Eventually it reaches it's limit as a nutrient sink and starts leaching out nutrients that no amount of water changes can fix. For me the only solution is swapping out the sand which is a dirty, potentially dangerous(for the inhabitants), chore.

If you don't siphon the detritus out of your sand regularly you have had it running just about the right amount of time to start having this very problem.

You should siphon out as much of the Cyano as possible when you do water changes but ultimately you have to get rid of the source of the nutrients or it will never go away. The Cyano may seem like the main problem currently, but it is really only a symptom of excess nutrients.

I used Chemiclean. Works great.

Seem to have heard and tried a lot of different "methods" but none seem to work. I have starved it, vacuumed it, used more flow, removed it, skimmed heavily, cut back on all foods, more water changes... I can't kill it. I remove it, go check on the tank... Looks spotless. Wake up in the morning, coated again.

How does one keep a sandbed clean? I was under the impression that they should not really be touched or disturbed... It's a 150 gallon system and I only have 7 fish. 6 small ones (two clowns, gramma, goby, pink fairy wrasse, lone chromis) and one medium ish fish a small scopas tang. So it's not a huge bioload... I don't know what gives.

FWIW, I've never cleaned my sand. Tank is 4 years old. Had cyano once due to lighting issues, used chemiclean, cleared it up.

+1 for chemiclean, follow the instructions well. It will send your skimmer crazy. For me, about 30% water change helped with the crazy skimmer issue.
Then keep your nutrients in check, although I don't know nearly enough to talk about that a still learning.
Brad, how do you keep a clean sand bed then ?

I couldn't get rid of it . 25% water changes three days in a row. Then every four days .
Run GFO !!

Wait .. Wait ... Each morning you should see a little less keep fighting until you see none for a week :)

Also I purged my sand and rocks with a turkey baster and made a mess and kept doing water changes like that . Nitrates hit zero fast. Phosphates hit zero.


Buy some snails that move the bed

It just stays clean on it's own. I have a few snail shells and frags and such lying around, but the detritus breaks down and is cycled by the bacteria, presumably. I might have a couple of the large nassarius snails, and a leopard wrasse, but that would have next to no impact.
I couldn't touch my sand bed in most of the tank even if I wanted to clean it, so never worried about it.

Interesting Brad, thx.
Good luck carriej, there are quite a few posts on here regarding cyano & controlling/getting rid of it. It looks like quite the year for it, although I am only 1 yr into reefing. I have read a lot where ppl say "it happens & is caused by high nutrients". Personally I truly believe mine & a friend's cyano came from corals (bought from the same tank that had cyano). Mind you, I have no definitive proof, but the timing was coincidental, about 2-3 wks afterwards. He is using tap water & I am using ro-di water. I have also now started using MB7, after cyano is gone (visibly), which I am understanding is a deterrent.