Hi Folks,
I'll try to keep things simple. Several months ago, I looked into my community tank to find my German Blue Rams (GBRs x 6) and Panda Garras (x2) sitting on the substrate barely moving. Their bodies had darkened and it looked as if they were paralyzed. It was a sorry sight. Just a few days before, they were full of life. What had happened? All the other fish - Cardinal Tetras, Otocinclus, Siamese Algae Eater, Pygmy Corydoras, C. habrosus were absolutely fine. This tended to rule out water parameters. Then, I remembered that there were a couple of small patches of BGA in the tank. The GBRs and Garras did not survive.
I therefore wondered if the Garras and GBRs may have taken a nibble of the BGA, which was on top of the filter outlet nozzle. This seemed a possibility for the Garras but not the GBRs but I was lost for any other explanation. I knew that some species of BGA were toxic to a whole range of creatures.
I set up a new tank using water from the tank in which I'd had the GBRs and Garras. It wasn't long before BGA started to grow. So, I removed a sample of this BGA and took a look at it under my second-hand school microscope. The objective was to see if I could identify the species of BGA that was growing. A quick detour here is now called for:
Blue-Green Algae (BGA) is not algae at all but is a species of Cyanobacteria. I had my suspicions of what species I had growing in my tank from what I'd read. My suspicion was that it was something called Oscillatoria. Its identifying feature is that the tips of the filaments of this Cyanobacteria oscillate from side to side. And, guess what I saw through the eyepiece of the microscope? Yes! - filaments waving from side to side.
To be continued...
JPC