Henk clearly you did something very wrong.... or the sheer quantity of algea was too much even for anti-biotics, leaving the lights off will at least hide the embaressment of peering into algaedom! :JumpfJ:
Cyanobacteria is that green algae stuff right? My Otos love the stuff, but I am afraid I need to help them out a bit since they have to come from behind in this race...
Yes, Cyano is Blue (Cyan) green (algae) algae, it's a symbiotic relationship between bacteria and algae and is probably one of the oldest life forms found on the planet. I doubt your Ottos eat it, nothing eats it (actually Ramshorn snails will munch on it), it's bad for fish and humans alike. In excess quantities in humans it may cause brain damage, although with some humans it may be hard to tell if it's Cyano or not .
Then I don't have cyano... My otocinclus cats definately munch on whatever I have. I like to sit and watch them feed and I promise you that I can see which stones they cleared during the night and as I watch them munch it they have this green poop coming out... And they are definately growing on the stuff... I am not feeding them anything as they eat this stuff and they are really flourishing, any idea what I have then?
If you rub the algae between your fingers does it have a pungent smell? If not then it's not cyano. You probably have what is known as Green spot algae, usually covers tank decorations and front glass panels.
Yup, doesn't pong... Is green spot then whoohoo!!! Wow I was worried there for a moment... These things are really attacking the plants... making dark green strands and I have to remove it with my fingers as the Oto's dont get to it in time...
Try cutting down your light cycle a bit and stop dosing so much iron. It's also better to just snip off the infected leaves as pulling at it makes it worse! This thread algae may take a while to go away but as soon as conditions are favourable for the plants it will slowly dwindle away. Freshwater shrimp like to nibble on it too. Florida flag fish (Killi) will also mow it down.